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Bibliography on: Microbial Ecology

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ESP: PubMed Auto Bibliography 27 Nov 2025 at 01:54 Created: 

Microbial Ecology

Wikipedia: Microbial Ecology (or environmental microbiology) is the ecology of microorganisms: their relationship with one another and with their environment. It concerns the three major domains of life — Eukaryota, Archaea, and Bacteria — as well as viruses. Microorganisms, by their omnipresence, impact the entire biosphere. Microbial life plays a primary role in regulating biogeochemical systems in virtually all of our planet's environments, including some of the most extreme, from frozen environments and acidic lakes, to hydrothermal vents at the bottom of deepest oceans, and some of the most familiar, such as the human small intestine. As a consequence of the quantitative magnitude of microbial life (Whitman and coworkers calculated 5.0×1030 cells, eight orders of magnitude greater than the number of stars in the observable universe) microbes, by virtue of their biomass alone, constitute a significant carbon sink. Aside from carbon fixation, microorganisms' key collective metabolic processes (including nitrogen fixation, methane metabolism, and sulfur metabolism) control global biogeochemical cycling. The immensity of microorganisms' production is such that, even in the total absence of eukaryotic life, these processes would likely continue unchanged.

Created with PubMed® Query: ( "microbial ecology" ) NOT pmcbook NOT ispreviousversion

Citations The Papers (from PubMed®)

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RevDate: 2025-11-26

Rajbhandari RM, Shrestha S, Manandhar P, et al (2025)

Comparing the respiratory tract microbiome in captive elephants and humans in Chitwan National Park: Implications for conservation medicine.

Comparative immunology, microbiology and infectious diseases, 125:102422 pii:S0147-9571(25)00130-4 [Epub ahead of print].

The study of gut microbiome in both animals and humans living in proximity has proven crucial in understanding their coevolution, the potential for microbial transfer and the dynamics behind various diseases. Similarly, the investigation of respiratory microbiomes has been gaining popularity due to its significance and impact on respiratory health. Here, we use 16S rRNA metabarcoding to explore the respiratory microbiome of captive Asian elephants (Elephas maximus) and their mahouts (i.e., trainers and handlers) in Chitwan National Park (Nepal), with local villagers residing out of the protected area acting as control. Sputum samples were collected to characterize their bacterial composition, while its functional profile was inferred with PICRUSt2. Additionally, the occurrence of genera hosting potentially pathogenic ESKAPE-E species was evaluated. Our findings revealed high similarity in the bacterial and functional composition of the respiratory microbiome of elephants and mahouts, with Bacillota and Pseudomonadota emerging as the most abundant phyla across all host categories and the controls displaying the highest diversity. A striking difference was observed in relation to the family Bacillaceae that dominated the microbial composition of both mahouts and elephants but not controls. Genera hosting potentially pathogenic ESKAPE-E bacteria were found in all host categories, which underscores the need for in-depth analyses to identify the species involved. Our study delivers valuable insights in the respiratory microbial community of both Asian elephants and humans, thus laying the basis for further investigations on their diversity and function, unveiling their role in respiratory health of both host species.

RevDate: 2025-11-26
CmpDate: 2025-11-26

Rettura F, Lambiase C, Bottari A, et al (2025)

Gut Virome: What's the Role in Irritable Bowel Syndrome?.

Reviews in medical virology, 35(6):e70080.

The gut virome, an integral but still poorly understood component of the gut microbiota, is emerging as an important player in the pathophysiology of irritable bowel syndrome (IBS). Recent evidence suggests that alterations in virome diversity and phage-bacteria interactions contribute to gut dysbiosis, immune modulation and gut barrier dysfunction in IBS. This review summarises current knowledge on virome alterations in IBS and emphasises the role of bacteriophages in shaping microbial ecology and host responses. Different virome signatures in the different subtypes of IBS highlight the potential of the virome for disease stratification and personalised therapeutic strategies. In addition, we discuss the analytical challenges in virome research and explore novel virome-targeted interventions, including phage therapy and dietary modulation. A deeper understanding of virome dynamics in the gut could open new avenues for precision medicine approaches to treat IBS.

RevDate: 2025-11-26

Guo M, Zhou Z, Zheng Y, et al (2025)

Ubiquity and Dominance of Comammox Over AOB and AOA and their Links To ARGs in Antarctic Lake Sediments.

Microbial ecology pii:10.1007/s00248-025-02664-4 [Epub ahead of print].

Complete ammonia oxidizers (comammox), oxidizing ammonia to nitrate directly, have been found to exist widely in multiple environments, but their distribution patterns are still under-explored in Antarctic environments. For the first time, the sediments were collected from West Antarctic lakes to investigate distribution patterns and community structure for comammox, ammonia oxidizing archaea (AOA) and bacteria (AOB), and nitrite-oxidizing bacteria (NOB), as well as the associations between ammonia oxidizers and antibiotic resistance genes (ARGs). Comammox clade B and AOB were dominant ammonia oxidizers, with the abundances of (1.62 ± 0.10) × 10[2] - (5.21 ± 0.74) × 10[6] and (0.17 ± 0.05) × 10[5] - (4.79 ± 0.65) × 10[5] copies g[- 1] sediment, respectively. Comammox clade B, instead of clade A, occurred in all sediments, exhibiting higher abundances than AOB and AOA in most of the sediments. The abundances for comammox clade B demonstrated significant positive correlation (p < 0.01) with NH4[+]-N levels, but negative correlation (p < 0.05) with C: N ratios. The coexistence of ammonia oxidizers in lake sediments was jointly structured by niche differentiation and environmental variables, and pH, modulated by penguin guano input, was found to be the most crucial factor in shaping their community structure. Co-occurrence network analyses revealed strong synergistic interactions between comammox and AOB, AOA, NOB, which played a critical role in nitrification processes. Our results further confirmed that comammox could act as important hosts for ARGs, hence stimulated their transmission and proliferation in the sediments. This study presented novel insights into the distribution patterns for ammonia oxidizers, their niche differentiation and the associations with ARGs in natural lake sediments of West Antarctica.

RevDate: 2025-11-26
CmpDate: 2025-11-26

Abdul Rahiman S, H Qiblawey (2025)

Anammox-MBR Technology: Breakthroughs and Challenges in Sustainable Nitrogen Removal from Wastewater.

Membranes, 15(11): pii:membranes15110337.

Wastewater nitrogen pollution is a serious environmental problem, and traditional treatment techniques are frequently constrained by their high energy requirements and operational complexity. The anaerobic ammonium oxidation (anammox) process combined with membrane bioreactor (MBR) technology (anammox-MBR) offers a practical and energy-efficient solution for the sustainable removal of nitrogen, further enhanced by its potential to minimize emissions of nitrous oxide (N2O), a potent greenhouse gas with a global warming potential nearly 300 times that of carbon dioxide. This review outlines the most recent advancements in anammox-MBR systems, highlighting their ability to achieve nitrogen removal efficiencies of more than 70-90% and, in integrated systems with reverse osmosis, to recover up to 75% of the inflow as high-quality reusable water. Significant advancements such as high-rate activated sludge coupling, reverse osmosis integration, microaeration methods, and membrane surface modifications have decreased membrane fouling, accelerated startup times, and enhanced system stability. Despite these achievements, there are still issues that hinder widespread use, such as membrane fouling exacerbated by hydrophobic anammox metabolites, sensitivity to low temperatures (≤10 °C), and the persistent challenge of suppressing nitrite-oxidizing bacteria (NOB), which compete for the essential nitrite substrate. To enable cost-effective, energy-efficient, and environmentally sustainable large-scale applications, future research directions will focus on creating cold-tolerant anammox strains, advanced anti-fouling membranes, and AI-driven process optimization.

RevDate: 2025-11-26
CmpDate: 2025-11-26

Špiljak B, Andabak Rogulj A, Lončar Brzak B, et al (2025)

Desquamative Gingivitis and the Oral Microbiome: Insights into Immune-Microbial Interactions in Mucosal Inflammation.

Dentistry journal, 13(11): pii:dj13110541.

Desquamative gingivitis (DG) is a clinical presentation characterized by erythema, epithelial desquamation, and mucosal fragility, commonly associated with immune-mediated diseases such as oral lichen planus (OLP), mucous membrane pemphigoid (MMP), and pemphigus vulgaris (PV). While traditionally viewed as a manifestation of immune dysregulation, growing evidence suggests that the oral microbiome may modulate disease onset, persistence, and severity. This review summarizes current knowledge on the oral microbiota in DG and its underlying diseases, explores mechanistic links between dysbiosis and immune activation, and discusses clinical and research implications. A narrative literature review was conducted using PubMed and Scopus, focusing on studies analyzing the oral microbiome in OLP, MMP, and PV. Emphasis was placed on molecular microbiology techniques, immune profiling, and functional or longitudinal approaches. In OLP, microbial dysbiosis is consistently reported, including reduced diversity and increased abundance of pro-inflammatory genera such as Fusobacterium, Prevotella, and Capnocytophaga. These shifts correlate with epithelial barrier disruption and inflammatory cytokine production. Although data on MMP and PV are limited, early findings suggest microbial involvement in sustaining inflammation, delaying healing, and possibly amplifying autoimmune responses. Dysbiosis may activate Toll-like receptors, skew T cell responses, and contribute to the breakdown of immune tolerance. DG may reflect a dynamic interplay between immune mechanisms and microbial ecology. While evidence is strongest for OLP, preliminary data suggest broader microbial contributions across DG-associated diseases. Microbiome-informed approaches could enhance diagnostic accuracy and support the development of adjunctive therapies.

RevDate: 2025-11-26
CmpDate: 2025-11-26

Schäfer RB, Baikova D, Bayat HS, et al (2025)

Effects of Biodiversity Loss on Freshwater Ecosystem Functions Increase With the Number of Stressors.

Global change biology, 31(11):e70617.

A multitude of anthropogenic stressors drive biodiversity loss and alter ecosystem functioning. Freshwaters, which contribute disproportionally to global biodiversity and biogeochemical cycles, are particularly threatened. Although the relationship between biodiversity and ecosystem functions (BEF) is generally well-established, especially in terrestrial ecosystems, the role of multiple, co-occurring stressors in modulating the relationship remains unclear. We conducted a meta-analysis to address this knowledge gap by assessing the effect of multiple stressors on the relationship between taxon richness and four measures of ecosystem function. The relationship was generally positive, with the slope becoming steeper as the number of stressors increased, suggesting that exposure to multiple stressors exacerbates impacts of biodiversity loss on ecosystem function. Multiple stressor effects on both taxon richness and ecosystem functions were largely predictable from individual stressor effects, although antagonistic effects on ecosystem functions emerged in 14% of the considered cases. The type of stressor and ecosystem function, along with taxonomic group, exerted no influence on the BEF relationship, contrary to our expectations. Microbial production and biomass declined most strongly in response to stressors, despite notable variability. Overall, our findings imply that functional consequences of freshwater biodiversity loss are more severe under multifaceted environmental change than previously assumed.

RevDate: 2025-11-26
CmpDate: 2025-11-26

O'Brien JM, Blais ND, Holland-Moritz H, et al (2025)

Consistent microbial responses during the aerobic thaw of Alaskan permafrost soils.

Frontiers in microbiology, 16:1654065.

Arctic systems are warming at four times the global average, causing permafrost-permanently frozen soil, ice, organic matter, and bedrock-to thaw. Permafrost thaw exposes previously unavailable soil carbon and nutrients to decomposition-a process mediated by microbes-which releases greenhouse gases such as carbon dioxide and methane into the atmosphere. While it is well established that thaw alters the composition and function of the permafrost microbiome, patterns revealing common responses to thaw across different permafrost soil types have not yet emerged. In this study, we address how permafrost thaw impacts microbiome diversity, alters species abundance, and contributes to carbon flux in the Arctic. We sampled peat-like, mineral, and organic-mineral permafrost from three locations in central and northern Alaska. We assessed their abiotic soil properties and microbiome characteristics before and after a 3-month laboratory microcosm incubation. Across all sites, prokaryotic biomass increased following thaw, measured as 16S rRNA gene copy number. This change in biomass was positively correlated with cumulative respiration, indicating an increase in microbial activity post-thaw. We evaluated the thaw response of microbial taxa across three sites, identifying taxa that significantly increased in abundance post-thaw. Common responders shared across all sites belonged to the families Beijerinckiaceae, Burkholderiaceae, Clostridiaceae, Oxalobacteraceae, Pseudomonadaceae, and Sporichthyaceae, indicating a common set of taxa that consistently respond to thaw regardless of site-specific conditions. Alpha diversity decreased with thaw across all sites, likely reflecting the increased dominance of specific thaw-responsive taxa that may be driving post-thaw biogeochemistry and increased respiration. Taken together, we deepen the understanding of different permafrost microbiomes and their response to thaw, which has implications for the permafrost-climate feedback and enables more accurate predictions of how Arctic ecosystem structure and function respond to change.

RevDate: 2025-11-25

Han H, Luo Z, Pei X, et al (2025)

Microbial-Plant Interaction: Bacillus subtilis-Driven Gravel Soil Improvement and Growth Promotion of Festuca arundinacea.

Microbial ecology pii:10.1007/s00248-025-02634-w [Epub ahead of print].

The rapid expansion of tunnel engineering in China has led to extensive excavation of gravelly soils, resulting in significant land occupation that threatens the ecological environment and surrounding biota. As a result, there is an increasing need for effective ecological restoration of nutrient-poor gravelly soils, where challenges in vegetation establishment and sustainable soil management persist. This study evaluates the potential of Bacillus subtilis to promote the growth of Festuca arundinacea in engineered gravel soils through a controlled greenhouse experiment, examining its effects on plant growth, soil nutrient dynamics, and microbial community structure. The results showed that, compared to the control group (CK), neither the Bacillus subtilis treatment group (Bs) nor the nutrient application treatment group (LB) significantly altered the soil bacterial species composition at the phylum level. However, at the genus level, Azotobacter dominated the LB group, while Sphingomonas was the predominant genus in both the CK and Bs groups. Additionally, Bacillus subtilis significantly increased bacterial diversity relative to the nutrient application treatment, leading to substantial changes in microbial community composition. Furthermore, Bacillus subtilis notably enhanced both aboveground and belowground biomass, improved nutrient uptake, and increased the availability of phosphorus and potassium. It also stimulated soil enzymatic activities involved in carbon, nitrogen, and phosphorus cycling, emphasizing its critical role in nutrient cycling. Thus, Bacillus subtilis-driven soil enhancement offers a promising solution for ecological restoration in nutrient-poor gravelly soils, where conventional amendments are often ineffective. These findings underscore the potential of microbial-plant synergies to improve soil fertility and support sustainable vegetation restoration.

RevDate: 2025-11-25

Jurado J, Garcia-Vega A, Vasquez Y, et al (2025)

Field-Scale AMD Remediation: Microbial Community Dynamics and Functional Insights in Biochemical Passive Reactors.

Microbial ecology pii:10.1007/s00248-025-02628-8 [Epub ahead of print].

Acid mine drainage (AMD) generated during coal mining activities is characterized by low pH, high concentrations of dissolved metals and metalloids, and elevated sulfate levels, all of which significantly impact surrounding ecosystems. Scaling up biochemical passive reactor (BPR) systems represents a promising approach for the in situ bioremediation of AMD. While numerous laboratory-scale studies have described the taxonomic and functional composition of microbial communities in BPRs, typically dominated by (ligno)cellulolytic organisms and sulfate-reducing bacteria (SRB), it remains unclear whether this composition is maintained at the field-pilot scale under environmental conditions. To address this gap, 16S rRNA gene metabarcoding and shotgun metagenomics analyses were performed to characterize the taxonomic and functional diversity of microbial communities in the BPRs within a multi-unit field-pilot system. The results revealed that bioremediation effectiveness was driven by syntrophic interactions among hydrolytic, fermentative, and sulfate-reducing bacteria, aligning with laboratory-scale observations. While community composition shifts altered specific taxa, core operational dynamics remained preserved.

RevDate: 2025-11-25

Zha Y, Fan L, Shen T, et al (2025)

Triptolide ameliorates LPS-induced acute lung injury in Balb/c mice through gut-lung axis-mediated regulation of bile acid metabolism and gut microbiota.

Scientific reports pii:10.1038/s41598-025-29758-w [Epub ahead of print].

Acute lung injury (ALI) associated with pulmonary edema is a severe clinical condition characterized by acute inflammation, disrupted lung barrier function, and high mortality. Current therapeutic strategies remain limited, highlighting the need for exploring novel agents and their underlying mechanisms. Triptolide (TP), an active component derived from Tripterygium wilfordii, has shown anti-inflammatory and tissue-protective properties[1,2], but its specific role in alleviating ALI and the involvement of the lung-gut axis in metabolic regulation remain poorly understood. This study aims to investigate the therapeutic effects of TP on LPS-induced ALI, focusing on its impact on pulmonary edema and inflammatory injury. By analyzing the lung-gut axis using multi-omics approaches, we seek to clarify the metabolic network regulatory mechanisms through which TP exerts its effects. LPS-induced ALI model was established in Balb/c mice, with TP administered as the therapeutic intervention. Histopathological examination of lung tissues and detection of pro-inflammatory cytokines were performed to assess lung injury. Untargeted metabolomics via LC-MS/MS was used to identify differential metabolites in lung tissues and serum, while metagenomic sequencing analyzed changes in gut microbiota composition. Integrated multi-omics analysis was applied to explore associations between gut microbiota alterations, serum metabolites, and pulmonary bile acid levels. TP administration significantly reduced histopathological damage in lung tissues of ALI mice and decreased pro-inflammatory cytokine levels. Metabolomics profiling revealed distinct changes in key metabolites, including bile acids, amino acid derivatives, and energy metabolism intermediates, in both lung tissues and serum after TP treatment. Metagenomic analysis showed that TP restructured gut microbiota composition, with functional enrichment in glycolysis and thiamine metabolism pathways. Integrated analysis confirmed strong correlations between dynamic microbiota changes, serum metabolite profiles, and pulmonary bile acid levels, indicating a regulatory role of the lung-gut axis. This study demonstrates that TP alleviates pulmonary edema and inflammatory injury in ALI by modulating gut microbial ecology and function, which drives bile acid metabolic reprogramming and regulates metabolite interactions within the lung-gut axis. These findings provide novel insights into TP's therapeutic mechanism and support its potential application in ALI treatment.

RevDate: 2025-11-25

Joshi H, Caprio M, Reon L, et al (2025)

Rumen Microbiota-Based Machine Learning Approach for Predicting Heat Stress and Identifying Associated Microbes.

Microbial ecology pii:10.1007/s00248-025-02656-4 [Epub ahead of print].

Heat stress poses a significant global challenge to sustainable livestock production, leading to detrimental impacts on animal production and welfare. Reduced appetite and increased body temperature further disrupt the gastrointestinal microbial ecosystem of heat-stressed animals, altering nutrient digestion and affecting host production. However, reported heat-stress-associated microbes have varied across studies, partly due to inconsistencies in microbiota analysis pipelines and taxonomic levels reported. In this study, to identify consistent rumen microbial taxa influenced by heat stress and evaluate potential of rumen microbiota in heat stress prediction, we collected publicly available raw 16S rRNA gene amplicon sequencing data of rumen fluid samples from lactating Holstein cattle housed in thermoneutral or heat stress condition from eight studies, analyzed their microbial composition using a consistent bioinformatic pipeline, and built machine learning models with the rumen microbiota profile to predict heat stress. Important rumen microbial taxa were selected using Boruta (a feature selection algorithm to identify important features) as potential biomarkers to predict heat stress, such as lactate-producing bacteria Lactobacillales, fiber-degrading bacteria Ruminococcaceae UCG-001, and methanogenic archaea Methanomicrobium. Additionally, the random forest model using the available animal factors and relative abundance of rumen microbial taxa showed a much higher performance for heat stress prediction, compared to the model without rumen microbiota profile (Area Under the Curve: 0.851 vs. 0.440). This study confirmed a distinct rumen microbiota signature in heat-stressed lactating Holstein cattle and identified specific rumen microbial taxa as potential biomarkers that could be targeted to mitigate heat-stress responses in dairy cows.

RevDate: 2025-11-25

Cohen DD, Faigenboim A, Elingold I, et al (2025)

Dynamics in Microbial Communities Associated with the Development of Soil Fatigue in Banana.

Microbial ecology pii:10.1007/s00248-025-02637-7 [Epub ahead of print].

Soil fatigue, well documented in various crops, presents a significant challenge to banana production by causing fast and then gradual declines in plant growth and yield over years of cultivation. Despite its impact on profitability, the underlying mechanisms driving soil fatigue remain poorly understood; however, a strong link to shifts in the soil microbiome has been suggested. We investigated the dynamics of microbial communities in relation to soil fatigue, using a novel semi-controlled outdoor experimental system. Soil at different stages of fatigue (0 to 42 months of banana cultivation) was generated in large containers filled with initially healthy soil. Banana plants grown in these soils were replaced with new plants which showed soil age-dependent growth. Three months postplanting, soil and root samples were collected for analyses of soil parameters and microbial community composition using bacterial (16S) and fungal (ITS) amplicon sequencing. We identified minor age-related shifts in mainly pH, potassium, and organic matter in the soil. While alpha diversity remained unchanged, significant shifts in bacterial and fungal community composition were observed in fatigued soils. Notably, the relative abundance of bacterial families such as Flavobacteriaceae, Pseudomonaceae, and Acidibacter increased, as did some fungal taxa (many from groups with known pathogens)-Ceratobasidiaceae (including Rhizoctonia), Dothideomycetes, and Stachybotryaceae. Simultaneously, the relative abundance of bacterial families with known beneficial members, including Gemmatimonadaceae, Moraxellaceae, Sphingomonadaceae, and Azospirillaceae, as well as symbiotic fungal taxa such as Glomeraceae and Lasiosphaeriaceae, declined. Thus, soil fatigue may be correlated to the proliferation of pathogenic populations and a loss of beneficial microorganisms.

RevDate: 2025-11-25

Katanić Z, Ćurković-Perica M, Idžojtić M, et al (2025)

Status of Dutch Elm Disease Fungus Ophiostoma novo-ulmi and Assessment of Its Temporal Variability in Croatia.

Microbial ecology pii:10.1007/s00248-025-02601-5 [Epub ahead of print].

Dutch elm disease (DED) was originally caused by the ascomycete Ophiostoma ulmi, which has been replaced by a more virulent species, O. novo-ulmi, divided into subsp. novo-ulmi and subsp. americana. Permeable reproductive barriers, a period of co-occurrence of O. ulmi and O. novo-ulmi, and the current overlap of O. novo-ulmi subspecies have been important in shaping the present O. novo-ulmi populations in Europe, which were initially clonal, predominantly of the MAT-2 type. This study confirmed the persistence of O. novo-ulmi in Croatia over the years, although at some forest sites, the diseased elms were not detected. The methodology used to assess changes in O. novo-ulmi populations was based on the col1 and cu genes, which have subspecies-specific nucleotide differences, analysis of MAT idiomorphs, and temperature-growth responses. The col1 and cu gene sequencing did not reveal a change in the number of isolates with the recombinant col1/cu genotype over 10 years (2012-2022). At both sampling times, approximately one-fourth of all analyzed isolates had recombinant col1/cu genotypes. However, the frequency of MAT-1 isolates, which all have MAT-1 genes originating from O. ulmi, increased during this period. Differences in growth rate at 20, 26, and 30 °C revealed variations in the temperature response of isolates, which were affected by sampling time and mating type. The MAT-1 isolates were shown to grow more slowly than MAT-2 at the three temperatures tested. The advantage of MAT-2 was reflected in temporal differences in growth rate at resampled sites, particularly at lower temperatures. These results suggest that changes in the frequency of mating types in Croatia occurred between 2012 and 2022, accompanied by modifications in the pathogen's response to temperature at the population level.

RevDate: 2025-11-25

Calbet A (2025)

Pelagic Shuttles of Antibiotic Resistance Genes: Zooplankton as Overlooked Vectors Across Space and Food Webs.

Microbial ecology pii:10.1007/s00248-025-02669-z [Epub ahead of print].

Antibiotic resistance genes (ARGs) accumulate in aquatic environments, where they create reservoirs and transmission pathways that can undermine antimicrobial treatments and alter the microbial community structure in ways that ultimately affect human and animal health. However, the contribution of zooplankton in these pathways remains critically overlooked. Emerging evidence shows that compared with surrounding water, copepods and cladocerans accumulate ARG loads that are one to two orders of magnitude greater, acting as microbial hotspots that disperse resistant bacteria across seasons and depths. Inside protistan vacuoles, densely packed prey cells undergo conjugation, rapidly accelerating horizontal ARG transfer. Long-term archives reveal persistent ocean-wide dissemination of the class-1 integron integrase (intI1) and sul2 genes since at least the 1970s. Here, I synthesize mechanistic and field evidence, pinpoint knowledge gaps, and recommend priorities: integrate zooplankton into routine ARG surveillance, quantify biofilm-mediated exchanges, and mitigate contamination from coselective pollutants to curb zooplankton-driven ARG propagation. By framing zooplankton-associated ARG dynamics within the broader community ecology of antimicrobial resistance, this mini-review highlights how aquatic food-web processes feed back into the emergence, evolution, and transmission of resistance that concerns for One Health outcomes beyond the clinic.

RevDate: 2025-11-25

Ishibashi S, Susukida S, Muto K, et al (2025)

Using pure oxygen aeration to increase recombinant protein production by an Aspergillus oryzae hyphal dispersion strain.

Journal of bioscience and bioengineering pii:S1389-1723(25)00277-4 [Epub ahead of print].

A high growth rate is essential for increasing protein production efficiency in liquid fermentation of filamentous fungi, such as Aspergillus oryzae. However, the increase in culture viscosity due to fungal growth constrains the overall yield. We have demonstrated that culture viscosity is lower in A. oryzae AGΔ-GAGΔ strains, which are deficient in the cell surface polysaccharides α-1,3-glucan (AG) and galactosaminogalactan (GAG), than in the wild-type (WT) strains. Nevertheless, even in aerated fermentation, an increase in AGΔ-GAGΔ viscosity results in oxygen depletion, which limits fungal growth and enzyme production. In this study, we investigated viscosity dynamics and protein production during high-cell-density fermentation of AGΔ-GAGΔ under pure oxygen aeration. Fed-batch cultivation of the WT and AGΔ-GAGΔ strains, expressing recombinant xylanase (XynF1), was used to compare the effects of air and pure oxygen aeration at the same flow rate. At 60 h, AGΔ-GAGΔ under pure oxygen aeration showed higher cell density (1.2× WT under pure oxygen aeration, 2.1× AGΔ-GAGΔ under air aeration) and XynF1 activity (1.8× WT under pure oxygen aeration, 2.3× AGΔ-GAGΔ under air aeration). Under pure oxygen aeration, AGΔ-GAGΔ showed lower viscosity (0.32×) and mixing time (0.50×) than WT. At 60 h, fine mycelial pellets (micropellets; 200-700 μm) were clearly observed in AGΔ-GAGΔ under pure oxygen but not under air aeration. These findings suggest that oxygen enrichment during AGΔ-GAGΔ cultivation mitigated the increase in viscosity, thereby promoting higher cell density and protein production. The formation of micropellets in AGΔ-GAGΔ likely contributed to a reduction in culture viscosity.

RevDate: 2025-11-25

Li C, Urem M, Kotsogianni I, et al (2025)

The novel GlcNAc 6-phosphate dehydratase NagS governs a metabolic checkpoint that controls nutrient signaling in Streptomyces.

PLoS biology, 23(11):e3003514 pii:PBIOLOGY-D-25-02640 [Epub ahead of print].

Streptomyces bacteria are renowned for their multicellular lifestyle and as Nature's medicine makers, producing the majority of the clinical antibiotics. A landmark event during early development is the lytic dismantling of the substrate mycelium. Degradation of the hyphal cell-wall leads to the accumulation of N-acetylglucosamine (GlcNAc) in the colonies, which is a metabolic checkpoint during the onset of development and antibiotic production. Here, we show that GlcNAc sensing requires a toxicity pathway dependent on the enzyme GlcNAc-6P dehydratase (NagS). Dehydration of GlcNAc-6P by NagS to 6P-chromogen I is an unprecedented reaction in central metabolism that is highly conserved in - and limited to - the Streptomycetaceae. 6P-chromogen I is metabolized into a structural analogue of ribose by a promiscuous activity of GlcNAc-6P deacetylase NagA. Toxicity is relieved by supplementing the growth media with ribose. Structure-function analysis of NagS not only highlighted key residues in the active site of the enzyme in interaction with its substrate GlcNAc-6P, but also revealed 6-phosphogluconate as its catalytic inhibitor. Our work uncovers a conserved metabolic toxicity pathway in Streptomyces that revolves around a novel enzyme that plays a key role in nutrient signaling.

RevDate: 2025-11-25
CmpDate: 2025-11-25

Ndabankulu KP, Zama N, Suinyuy TN, et al (2025)

Soil Microbe Interaction and Extracellular Enzyme Activity Mediated by Encephalartos villosus in KwaZulu-Natal Scarp Forest Ecosystems.

Microbial ecology, 88(1):132.

Cycads are ancient gymnosperms that play a crucial role in the soil health of scarp forests through their symbiotic associations with nutrient-cycling bacteria. However, the abundance of cycads in scarp forests has been decreasing at an alarming rate, highlighting the importance of determining the role of these species in nutrient cycling, microbial dynamics, and soil health. This study examined soil nutrient and microbial dynamics associated with Encephalartos villosus across four scarp forest sites in KwaZulu-Natal, South Africa. Soil samples were collected from the rhizosphere and non-rhizosphere zones (3-5 m away from the canopy) of mature plants. Results show that collection point did not influence soil nutrient and properties statistically; however, site-level variation was evident, with Hlathikhulu showing higher pH and nutrient concentrations, while Vernon Crookes exhibited lower pH and nutrient availability. Rhizosphere soils supported a greater diversity of nutrient-cycling bacteria, particularly taxa from the genera Bacillus, Burkholderia, Enterobacter, Luteibacter, and Pseudomonas with N-fixing, P-solubilizing, and N-cycling functions. Non-metric multidimensional scaling (NMDS) revealed that site differences, mainly driven by Mg, Ca, K, Zn, pH, and total cations, were stronger predictors of soil nutrient and microbial community variation than collection point alone. Enzyme assays showed that glucosaminidase and acid phosphatase were associated with community differences. These findings indicate that E. villosus enhances soil nutrient enrichment and microbial functional diversity in scarp forests, although the strength of these effects depends on local site conditions. Conservation of E. villosus is therefore critical, not only for species survival but also for sustaining soil fertility and ecosystem functioning in nutrient-limited scarp forest habitats.

RevDate: 2025-11-25
CmpDate: 2025-11-25

Kim J, Cui Y, Nam KH, et al (2025)

Effects of CP4-EPSPS-Containing Brassica juncea Hybrids on the Gut and Fecal Microbiota of the Terrestrial Decomposer Armadillidium vulgare.

Microbial ecology, 88(1):131.

The unintended spread of genetically modified (GM) crops and introgression into wild relatives raises concerns about ecological impacts. In South Korea, CP4-EPSPS-containing Brassica juncea hybrids (GM-hybrid B. juncea) have been detected in natural ecosystems. However, the impact of these GM crops on ecology remains unclear. In this study, we aimed to investigate the potential effects of GM-hybrid B. juncea on the gut and fecal microbiomes of Armadillidium vulgare, a dominant decomposer in natural habitats and an ideal model organism for assessing the ecological impact of GM plant material. Leaf litter from wild-type and GM-hybrid B. juncea was collected from the field, and feeding experiments were conducted using A. vulgare under controlled conditions. Although no significant differences in survival rates or growth were observed between groups, microbiome analysis revealed significant changes in both bacterial and fungal community composition and functional profiles in the gut and feces of the GM-hybrid-fed group. Specifically, in the GM-hybrid-fed group, the proportion of intestinal Plectosphaerella (Glomerellales) increased. Additionally, the bacterial Shannon index decreased, whereas the fungal Shannon index increased. Microbial network analysis revealed distinct interaction patterns and GM-hybrid-specific modules. GM-hybrids may influence decomposer-associated microbiomes through indirect pathways. Such influences could affect ecosystem-level processes such as decomposition and nutrient cycling. This experimental framework can be extended to other crop-derived hybrids or applied to different ecological contexts, providing a valuable basis for future assessments of transgene impacts on ecosystem functions.

RevDate: 2025-11-25
CmpDate: 2025-11-25

Yang W, Deng Z, Blair D, et al (2025)

Heavy-metal Pollution Affects Daphnia Fitness by Altering Diversity of the Gut Microbiota.

Microbial ecology, 88(1):130.

The role of gut microbiota in shaping host fitness is already well established. However, it remains unclear to what extent the gut microbiota influences host fitness in the presence of environmental stressors. Here, we tested the hypothesis that responses of water flea Daphnia to the heavy metal nickel are mediated by gut microbiota. Germ-free D. magna exhibited somewhat lower fitness than did those with gut microbiota transplant. Among germ-free Daphnia, those that were exposed to heavy metals did not differ in fitness from unexposed Daphnia. In contrast, when incubated with their donors' gut microbiota, initially germ-free D. magna continuously exposed to nickel for 21 days showed a significantly lower survival rate than those not exposed to nickel. We detected a reduced set of microbes in the formerly germ-free Daphnia in the presence of nickel. Transcriptomic analysis of Daphnia showed that expression/regulation of genes related to oxygen transport, chitin metabolism, and detoxification changed in response to the reduced gut microbiomes acquired in the presence of nickel. Our findings show that the toxic effects of heavy metal led to a reduced diversity of gut microbiota in Daphnia and can thus affect host fitness.

RevDate: 2025-11-25
CmpDate: 2025-11-25

Wardhani R, Shin J, Lee S, et al (2025)

Evaluation of Aquamicrobium lusatiense NLF 2-7 as a Biocontrol Agent in Manure Composting: Effects on Odorous Compounds and Microbial Community Under Mesophilic Conditions.

Microbial ecology, 88(1):129.

Microbial inoculation is a commonly applied approach in composting to enhance organic matter biodegradation and reduce odor emissions. However, the different characteristics of bacteria in terms of temperature can be considered to optimize their effect during different phases of composting. A mesophilic bacterium, namely Aquamicrobium lusatiense NLF 2-7, was evaluated to mitigate odor emissions and enhance the bacterial community under mesophilic composting. Two different treatments were designed: treatment 1 with a single inoculation on the initial day and treatment 2 with split inoculation at the initial and after 2 weeks. Results show that the treatments improve organic matter decomposition by 17.7-28.6% and significantly reduce volatile sulfur compound emissions, especially dimethyl sulfide (DMS) and hydrogen sulfide (H2S) during the initial phase of composting. DMS emissions were mostly emitted in the first week, with reduction rates of 60.3% and 61.5% in both treatments, respectively. Additionally, mean phenol emissions were reduced by 7.9% in treatment 1 and 11.7% in treatment 2. The dominant bacterial phyla during composting were Bacillota, Pseudomonadota, Bacteroidota, and Actinomycetota, comprising 74 to 95% of the total population. This experiment suggests that A. lusatiense NLF 2-7, which is known for reducing sulfur emissions, can also enhance organic matter decomposition. Split inoculation appears more beneficial, with an initial inoculation managing sulfur emissions early on, followed by a second inoculation after the thermophilic phase to control phenol emissions throughout the composting process.

RevDate: 2025-11-25

Taheri S, Schwarzkopf E, Berman HL, et al (2025)

The role of flour type and feeding schedule on the sourdough microbiome.

Microbiology spectrum [Epub ahead of print].

Sourdough starters are fermentations of various grains by bacteria and yeast and are of worldwide economic and cultural importance. Sourdoughs are sometimes spontaneously inoculated, and their resident microbial communities are in part shaped by environmental factors, potentially including flour, water, air, human microbiota, equipment, geography, and temperature. The number of different genera of bacteria and yeast found in sourdoughs is large; however, only a handful of species typically dominate an individual sourdough starter. Understanding how and why certain species form a mature climax community in a particular environment is a key question in microbial ecology. To investigate this question, we used a meta-barcoding approach and tested whether different baking flours (all-purpose, bread, and whole wheat) and frequency of feeding, also known as backslopping, shape the sourdough starter microbial community over the course of one month. We found that the yeast genus Kazachstania rapidly rose in frequency and became the most abundant yeast in all starters, regardless of flour type or feeding schedule. In contrast, flour type did affect the bacterial community. Mature sourdoughs all contained the bacterial genera Companilactobacillus, Levilactobacillus, Lactiplantibacillus, Furfurilactobacillus, and Acetobacter, with Companilactobacillus detected at higher relative abundance in whole wheat flour and Levilactobacillus detected at higher relative abundance in bread flour. We conclude that flour can shape the microbial community of sourdough and has potential implications for functional traits.IMPORTANCEHow organisms disperse and colonize new environments is central to our understanding of biodiversity. Sourdough, the often spontaneously inoculated fermentation of grains by bacteria and yeast, represents a great system to test and observe how microorganisms come to inhabit a particular niche. In our study, we investigate how environmental parameters such as flour type and feeding frequency influence the microbial community. We find that the common sourdough yeast genus Kazachstania is most abundant in all starters regardless of treatment, but we also find a significant effect of flour type on the lactic acid bacteria composition of the sourdough starters. This work shows how the environment can impact the presence and abundance of particular microorganisms and prompts future studies to test how particular lactic acid bacteria species can specialize on certain resources.

RevDate: 2025-11-25
CmpDate: 2025-11-25

Wang H, Yang Y, Zhang H, et al (2025)

Symbiotic N-Fixing Bacteria in the Root and Leaf of Typical Alpine Grassland Plants.

Microbial ecology, 88(1):127.

Alpine plants in nitrogen-deficient environments can acquire nitrogen by associating with endophytic nitrogen-fixing microorganisms that inhabit their roots and leaves to form symbiotic relationships. However, research is limited on nitrogen-fixing bacterial communities in the roots and leaves of alpine grassland plants, especially regarding the differences between various plant parts. In this study, we compared the root and leaf bacterial communities of four alpine plant families (Asteraceae, Leguminosae, Poaceae, and Rosaceae) in the alpine meadow ecosystem of Naqu, Tibet, using culture-based methods, 16S rRNA, and nifH gene pyrosequencing. The results showed greater bacterial diversity in the root compared to the leaf, and Fabaceae plants harbored a higher abundance of nitrogen-fixing bacteria. Interestingly, the roots and leaves of non-Fabaceae plants (Kobresia, Festuca ovina, and Leontopodium) also harbored abundant nitrogen-fixing communities such as Microbacterium, Curtobacterium, and Rhodococcus. Compared with subtropical environments, Cyanobacteria are important symbiotic nitrogen-fixing bacteria in plants of alpine ecosystems. These findings indicate that plant species and plant parts strongly influence the selection of bacterial populations. Understanding these microbial ecological functions in alpine grasslands provides scientific insights for optimizing agricultural practices and ecosystem management.

RevDate: 2025-11-25

Jones AK, Jordan HR, Wolff CL, et al (2025)

Lasting Effects of Different Scaled Mass Mortality Events on Soil Microbial Communities.

Microbial ecology pii:10.1007/s00248-025-02625-x [Epub ahead of print].

Death is a natural process present in all ecosystems; however, mass mortality events are instances of larger than average numbers of animals dying in a relatively short period of time. These events are increasing in frequency and magnitude, and the effects of mass mortalities - especially their long-term effects - are understudied. To better understand the long-term effects of mass mortalities in terrestrial ecosystems, we conducted experimental mass mortality events to determine if key ecosystem properties remained affected after 4 years. The experiment crossed three types of input treatments (control, carrion, and nutrient additive) with scavenger access (open plots versus fenced plots). To evaluate how increasing carrion biomass affected the ecosystem, sites were randomly assigned biomass (25, 59, 182, 363, 726 kg total (20m[2] plots)). Biomasses consisted of feral swine carcasses or the equivalent amount of N, phosphorus, and K nutrients. After 4 years, we found that while soil N did not differ among treatments, soil K and Ca significantly increased with biomass. Microbial communities significantly differed at the 182 kg biomass treatments compared to others and indicated significant effects between carrion and nutrient additive treatments. These results demonstrate that large die-offs, such as mass mortality events, can have long-lasting effects on soil composition through increased soil nutrients and alter soil microbial community (i.e., reduced Bacilliaceae, etc.). These long-lasting impacts can permanently alter the soil community, which can lead to cascading bottom-up effects that can alter the entire ecosystem structure.

RevDate: 2025-11-25

Bondarenko S, Obiol A, Casamayor EO, et al (2025)

Non-Dikarya Fungal Clades Are Everywhere: What 18S rRNA Gene Metabarcoding Reveals About Cross-System Distribution of Fungi.

Microbial ecology pii:10.1007/s00248-025-02642-w [Epub ahead of print].

Non-Dikarya fungi remain poorly characterized due to their cryptic morphology, cultivation difficulties, and limited representation in reference databases. To investigate their diversity and environmental distribution at a global scale, we reanalyzed over 6000 environmental samples using metabarcoding targeting the V4 region of the 18S rRNA gene, encompassing marine, freshwater, soil, hypersaline, polar, and other habitats. We constructed reference phylogenetic trees based on near full-length 18S rRNA gene sequences to enable accurate placement of short-read amplicon sequence variants (ASVs). This approach yielded robust classification at the phylum level and provided finer-scale clade resolution within major non-Dikarya groups. We delineated precise clades within Chytridiomycota, Microsporidia, Rozellida, and Aphelidea, and unveiled several novel ones. Our results show strong ecological structuring of fungal communities across habitats, with inland systems harboring greater fungal abundance and broader phylogenetic diversity than marine systems. Non-Dikarya fungi were consistently detected across diverse environments, including extreme habitats such as hypersaline lakes, deep sediments, and polar regions, where they were often the dominant fungal taxa. Although most ASVs tended to occur in a limited number of ecologically related habitats, phylogenetically related ASVs within the same clade were often adapted to different environments, indicating ecological diversity within clades. Our findings underscore both the ecological relevance and the cryptic diversity of non-Dikarya fungi in globally distributed environments, including extreme ones. Improved taxonomic resolution and broader reference dataset coverage are required to fully integrate these newly characterized lineages into fungal systematics and environmental surveys.

RevDate: 2025-11-25

García-Gutiérrez L, Mellado E, PM Martin-Sanchez (2025)

Contribution of DNA Metabarcoding to the Environmental Fungal Assessments in Hospitals.

Microbial ecology pii:10.1007/s00248-025-02626-w [Epub ahead of print].

Hospitals are particularly sensitive environments where immunosuppressed patients might acquire invasive fungal infections. Therefore, it is necessary to carry out periodical environmental microbiological assessments that evaluate the fungal bioburden in air and surfaces from different hospital zones. Current microbiological monitoring protocols at healthcare settings are mostly based on cultivation, while environmental DNA (eDNA) assessments are still scarce and should be further evaluated. To fill this gap, this study combines a large sampling scheme, comprising > 200 samples (air, surface, dust and soil) collected from four zones at three Spanish hospitals in two campaigns (winter and autumn), with two eDNA approaches (DNA metabarcoding and quantitative PCR) to characterize the hospital mycobiomes (diversity, community composition and airborne load), compared to a parallel culture-dependent study. DNA metabarcoding revealed a much more comprehensive inventory of hospital fungi compared to culturing; however, both approaches found similar dominant taxa including a variety of potentially opportunistic human pathogens. Hospital mycobiomes were affiliated to 4 phyla (mostly Ascomycota and Basidiomycota), 35 classes, 114 orders, 305 families, 643 genera and 535 species. The dominant genera, in both air and surfaces from the three hospitals, were Cladosporium, Alternaria, Aureobasidium, Penicillium, Neodidymelliopsis, Aspergillus, Pseudopithomyces and Stemphylium. The yeasts Candida and Clavispora were particularly abundant on high-touch surfaces indoors. The most important explanatory factors for the variance in community composition were the hospital and zone where samples were collected, the type of sample and the sampling campaign. DNA metabarcoding can assist hospital managers by providing an in-depth characterization of the baseline hospital mycobiome during normal operating conditions, as well as identifying and controlling community imbalances and associated health risks under demanding situations such as construction works or reported clinical outbreaks.

RevDate: 2025-11-25

Sultanova Z, Dönertaş HM, Hita A, et al (2025)

Age-Dependent Gut Microbiota Dynamics and Their Association with Male Life-History Traits in Drosophila melanogaster.

Microbial ecology pii:10.1007/s00248-025-02640-y [Epub ahead of print].

Growing evidence suggests that the gut microbiota is closely intertwined with life-history evolution in a wide range of species, including well-studied model organisms like Drosophila melanogaster. Although recent studies have explored the relationship between gut microbiota and female life-history, the link between gut microbiota and male life-history remains relatively unexplored. In this study, we investigated how gut microbiota changes with male age as well as the associations between gut microbiota composition and male life-history traits in D. melanogaster. Using 22 isolines from the Drosophila melanogaster Genetic Reference Panel (DGRP), we measured lifespan, early/late-life reproduction, and early/late-life physiological performance. We characterized the gut microbiota composition in young (5 days old) and old (26 days old) flies using 16S rDNA sequencing. We observed substantial variation in both male life-history traits and gut microbiota composition across isolines and age groups. Using machine learning, we show that gut microbiota composition could predict the chronological age of the organisms with high accuracy. The most important species contributing to machine learning prediction belonged to the Acetobacter and Ralstonia genera. Associations between gut microbiota and life-history traits were also notable, particularly involving different species from the Acetobacter genus. Our findings suggest that taxa such as Acetobacter may be relevant to the evolutionary ecology of host-microbe interactions in male fruit flies.

RevDate: 2025-11-25
CmpDate: 2025-11-25

Liu XQ, An XP, He WX, et al (2025)

Hairy Vetch Intercropping Attenuates Mycorrhizal Benefits to Walnut Growth and Soil Organic Carbon Sequestration via Glomalin.

Microbial ecology, 88(1):128.

Intercropping is a prevalent soil management strategy within walnut orchards, while its impacts on the functionality of arbuscular mycorrhizal fungi (AMF) in walnuts (Juglans regia) remain unclear, especially concerning soil carbon (C) sequestration via glomalin-related soil protein (GRSP). This study aimed to explore the effects of inoculation with the AMF species Diversispora spurca and intercropping with hairy vetch (Vicia villosa) on walnut biomass accumulation, soil water-stable aggregate (WSA) stability, leaf and root C (Cleaf and Croot) content, soil organic carbon (SOC), GRSP, and GRSP-contained C (CGRSP), in addition to the contribution rate of CGRSP to SOC. The intercropping treatment significantly inhibited root mycorrhizal colonization rate, soil hyphal length, and spore density in AMF-inoculated walnut plants. Individual AMF inoculation, rather than individual intercropping, significantly promoted shoot and root biomass accumulation, WSA stability, SOC, Cleaf and Croot, the levels of purified easily extractable (EEG), difficultly extractable (DEG), and total GRSP (TG), as well as their C contents. The combination treatment (AMF inoculation + intercropping) displayed limited benefits, improving just WSA stability without yielding synergistic advantages over individual treatments. Arbuscular mycorrhizal fungal inoculation significantly increased CGRSP, especially CDEG, while individual intercropping resulted in a reduction of CDEG. The combination treatment elevated both CDEG and CTG, albeit to a lesser extent than AMF alone. The contribution rates of CEEG, CDEG, and CTG to SOC were 0.33% - 0.53%, 1.16% - 1.78%, and 1.49% - 2.31%, respectively. Although AMF inoculation significantly increased the contribution rates of CDEG and CTG to SOC, this effect was diminished when combined with intercropping. Notably, CDEG, rather than CEEG, exhibited a significantly positive correlation with SOC and WSA stability. The findings provide new insights into the mechanisms of SOC sequestration in walnuts grown in controlled environments and offer a theoretical basis for the application of AMF in walnut cultivation.

RevDate: 2025-11-24

Song H, Dowdell K, Delafont V, et al (2025)

The Neglected Role of Heterotrophic Protists in Engineered Water Systems.

Environmental science & technology [Epub ahead of print].

Heterotrophic protists can be considered the dark matter of microbial communities in engineered water systems. They are ubiquitous and ecologically significant yet remain largely overlooked. Although a growing body of research demonstrates their pivotal roles (e.g., predation, symbiosis, and nutrient cycling) in microbial communities in natural ecosystems, their functions in engineered water systems are poorly characterized, and heterotrophic protists are frequently excluded from microbial analyses. This is largely due to methodological constraints that have only recently been overcome. Recent advances in imaging, high-throughput sequencing, and meta-omics approaches, combined with expanding reference databases, have revolutionized studies of protist diversity and functions in a wide range of natural environments. Drawing on research from the fields of protistology, microbial ecology, and environmental microbiology, this review explores how the well-documented ecological roles of heterotrophic protists in natural environments translate to engineered ecosystems, offering insights into their functions in water treatment. We critically evaluate recent literature to synthesize both beneficial roles and potential risks of heterotrophic protists in various water treatment systems, while identifying key knowledge gaps and proposing directions for future research. We advocate for a shift in perspective that recognizes heterotrophic protists as important players and call for their integration into microbial community characterization and ecological frameworks in microbial ecology studies of engineered water systems. This integration will transform our understanding of microbial communities in engineered water systems, ultimately enabling novel, mechanistic, and ecologically informed management strategies.

RevDate: 2025-11-24
CmpDate: 2025-11-24

Ganguly D, Roy R, Mondal P, et al (2025)

Nisin, a promising antimicrobial peptide, forestalls the methicillin-resistant Staphylococcus aureus biofilm network via reactive oxygen species generation.

3 Biotech, 15(12):428.

UNLABELLED: Staphylococcal infections have been reported to be a significant global threat to the effective management of public healthcare due to their drug resistance property. This attribute has further been complicated by their robust biofilm-forming potential. This escalating threat of biofilm-associated infections necessitates innovative and promising therapeutic strategies. Hence, in the present study, the biofilm threat of methicillin-resistant Staphylococcus aureus (MRSA) has been challenged by Nisin, a natural lantibiotic produced by Lactococcus lactis. This compound showed a promising antibacterial effect with minimum inhibitory concentrations (MICs) of 150 µg/ml against MRSA. Furthermore, a series of experiments has been conducted to confirm the antibiofilm potential of Nisin against MRSA. Towards this direction, the sub-MIC dose of Nisin (40 µg/mL) was found to inhibit biofilm formation by ~ 51% for MRSA. To support this finding, extracellular polymeric substance (EPS) was measured under the Nisin-treated and untreated conditions of MRSA. It was observed that Nisin could destabilise the MRSA biofilm by reducing the EPS production to an extent of ~ 55%. Mechanistic studies further demonstrated that Nisin was found to increase the intracellular accumulation of reactive oxygen species (ROS), which could lead to the alteration of cell membrane permeability. Additionally, Nisin attenuated staphyloxanthin production (~ 54%), hemolytic ability (~ 26%), and fibrinogen clumping ability (~ 27%) of MRSA, suggesting its interference in the virulence profile of MRSA. Collectively, these findings suggest Nisin's dual role as a promising Staphylococcal biofilm inhibitor and virulence factor suppressor, making it a viable option for the treatment of MRSA-linked infections.

SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s13205-025-04597-8.

RevDate: 2025-11-24
CmpDate: 2025-11-24

Dely A, Racicot R, Samples R, et al (2025)

Draft genome sequence and metabolomics data for Streptomyces sp. ADLamb9 isolated from the rhizosphere of Lavandula dentata.

Data in brief, 63:112199.

Iron-chelating molecules or siderophores play pivotal roles in soil ecosystems, particularly in facilitating plant iron uptake as well as the phytoremediation of metal-polluted environments. Lavandula dentata, commonly referred to as French Lavender, is a valuable species for siderophore production due to its ability to thrive in iron-deficient Mediterranean soils by forming symbiotic relationships with siderophore-producing rhizosphere microbes. Here, we used a Chrome Azurol S (CAS) overlay assay to isolate a yellow-pigmented L. dentata rhizosphere siderophore-producing bacterium. This isolate also demonstrated antibacterial and antifungal activities against Bacillus subtilis and Aspergillus flavus, respectively. Genomic sequencing revealed that the isolate was Streptomyces sp. ADLamb9 with a genome size of 8.2 Mb and 71.77% GC content. antiSMASH analysis of the Streptomyces sp. ADLamb9 genome identified four putative siderophore biosynthetic gene clusters as well as the catecholate siderophore mirubactin. Liquid chromatography-tandem mass spectrometry (LC-MS/MS) masses consistent with desferrioxamine B (561.3604 m/z), IC202C (517.3342 m/z), mirubactin (605.2207 m/z), as well as previously unreported desferrioxamine A1C. Notably, the presence of the rare earth element cerium differentially affected the accumulation of catecholate and hydroxamate siderophores, highlighting our incomplete understanding of the complex regulation and relationship between siderophore biosynthesis genes. These datasets, deposited at NCBI under the BioProject accession number PRJNA1224804, contribute to the broader scientific understanding of metabolite diversity and genomic features of Streptomyces sp. ADLamb9, providing insight into its use in bioremediation, especially in the presence of rare earth elements.

RevDate: 2025-11-24

Qian M, Zhu D, Yao K-y, et al (2025)

Coexistence of virome-encoded health-associated genes and pathogenic genes in global habitats.

Applied and environmental microbiology [Epub ahead of print].

UNLABELLED: Viral remnants constitute approximately 8% of the human genome, reflecting extensive historical gene exchange between viruses and their hosts. Some viral genomes harbor genes acquired through horizontal gene transfer that are associated with potential benefits to human health, alongside genes associated with pathogenicity. However, their global distribution, functional characteristics, and coexistence patterns remain poorly understood. Here, using the Integrated Microbial Genomes and Virome (IMG/VR v4) database, we identified 4,556 viruses carrying gene segments associated with human health across eight habitat types spanning 13 regions and 76 countries worldwide. Among viruses with identifiable hosts, those distributed in humans (478) accounted for the highest proportion. The viral genes associated with human health included BCO1 (beta-carotene oxygenase 1), bioB (biotin synthase), COQ2 (4-hydroxybenzoate polyprenyltransferase), GPX1 (glutathione peroxidase 1), GSTs (glutathione transferases), GSTT1 (glutathione S-transferase theta 1), GULO (L-gulonolactone oxidase), and menA (1,4-dihydroxy-2-naphthoate polyprenyltransferase). These genes not only associate with human health but also function as auxiliary metabolic genes in viral genomes. Notably, four pathogenic genes were found in viral sequences carrying health-associated genes, with potential for transcription and expression, indicating functional interactions. Experimental transduction of the viral bioB gene into Escherichia coli altered the expression of host pathogenic genes GCH1 (GTP cyclohydrolase IA) and UGDH (UDP-glucose 6-dehydrogenase), supporting potential cross-regulatory interactions. Overall, this study incorporates health-associated genes into viral genomics, highlighting their coexistence with pathogenic genes, and provides new insights into virus-host coevolution and potential biotechnological applications.

IMPORTANCE: Viruses are the most abundant biological entities on Earth and key drivers of microbial evolution through horizontal gene transfer. While often studied for their pathogenic effects, viruses can also carry genes that influence host metabolism and health. Genes associated with human health have been identified in viral genomes, yet their global distribution, functions, and coexistence with pathogenic genes remain largely unexplored. This study integrates datasets of health-associated genes into viral genomic analyses, revealing for the first time the coexistence of viral health-associated genes with those linked to pathogenicity. This dual genetic potential is observed across diverse habitats, highlighting viruses as multifaceted reservoirs of both beneficial and harmful genes. The study findings advance understanding of viral functional diversity and open new avenues for exploring viral roles in microbial ecology, biotechnology, and human health.

RevDate: 2025-11-24
CmpDate: 2025-11-24

Bron A, Beltramo C, Durif C, et al (2025)

Small intestine is not colon: a new in vitro model of the human ileum microbiome integrating the mucosal microenvironment and feeding status.

Gut microbes, 17(1):2579353.

The small intestinal microbiota plays a key role in human health but is understudied due to the invasiveness of sampling. There is no available model of the human ileal microbiome simulating the key nutritional and physicochemical parameters shaping this ecosystem, which has been fully validated based on in vivo data. Here, the Mucosal Artificial Ileum (M-ARILE) was set up to reproduce the pH, transit time, anoxic conditions, dynamics of feeding and microenvironments (luminal versus mucosal) found in a healthy human mid-ileum. To validate the newly developed in vitro system, nine-day fermentations were performed under either ileal or colonic conditions using the same fecal inoculum (n = 3 adult volunteers). The gut microbiota composition and metabolic activities were monitored daily. Distinct microbial signatures and metabolite profiles were obtained between in vitro ileum and colon conditions. In accordance with in vivo data, Peptostreptococcaceae, Clostridiaceae and Enterococcaceae were enriched in the ileum and associated with lower short-chain fatty acid production but higher O2 percentages. Interestingly, the abundances of key populations, such as Akkermansiaceae, and bile acid profiles were dependent on the feeding status of the M-ARILE. This new model provides a powerful platform for mechanistic studies on the role of ileal microbes in human nutrition and health considering inter-individual variabilities.

RevDate: 2025-11-23
CmpDate: 2025-11-23

Su Z, Zhang X, Wang Q, et al (2025)

amplysis: an R package for microbial composition and diversity analysis using 16S rRNA amplicon data.

Briefings in functional genomics, 24:.

The downstream analysis of 16S rRNA sequencing data remains a significant challenge for researchers lacking extensive bioinformatics expertise, often requiring proficiency in diverse tools and methodologies. To address this, we present amplysis, an R package designed to streamline the analysis and visualization of 16S rRNA amplicon sequencing data through an intuitive, code-light workflow. amplysis integrates data importing, processing, statistical analysis, and visualization into a unified framework. Key features include data normalization, microbial composition profiling, alpha/beta diversity analysis, ordination methods (e.g. Principal Component Analysis), and publication-ready visualization tools. The package's utility was demonstrated through three case studies, one of which analyzed microbial community responses to hexachlorocyclohexane (HCH) degradation in groundwater environments. Using amplysis, we efficiently generated phylum/genus-level abundance plots, alpha-diversity indices, and Principal Coordinates Analysis ordination, revealing significant shifts in community structure and diversity under HCH stress. The other case studies utilized publicly available data from published studies by other researchers. These results underscore the package's ability to simplify complex analyses while ensuring reproducibility and high-quality output. By integrating modular, user-friendly functions, amplysis lowers the barrier to robust microbiome data exploration. The package is available on GitHub (https://github.com/min-perilla/amplysis), offering a valuable resource for researchers in microbial ecology and environmental genomics.

RevDate: 2025-11-22

Naziębło A, Pytlak A, Furtak A, et al (2025)

Advances and Hotspots in Research on Verrucomicrobiota: Focus on Agroecosystems.

Microbial ecology pii:10.1007/s00248-025-02657-3 [Epub ahead of print].

Members of the phylum Verrucomicrobiota are abundant yet relatively understudied soil bacteria that play key roles in biogeochemical cycling and plant-microbe interactions. They participate in the carbon (C) and nitrogen (N) cycles through the degradation of complex organic polymers such as cellulose, pectin, and starch - via the production of hydrolytic enzymes (e.g., cellulases, xylanases, chitinases), and through nitrogen transformations including denitrification, ammonification, and nitrogen fixation. Methanotrophic representatives (Methylacidiphilum, Methylacidimicrobium) oxidise methane under acidic or thermophilic conditions, thereby contributing to greenhouse gas mitigation. The ecological distribution and activity of Verrucomicrobiota are strongly influenced by nutrient availability, particularly of C, N, phosphorus (P), and potassium (K). Their variable responses to these elements reflect diverse life-history strategies, encompassing both copiotrophic (r-strategist) and oligotrophic (K-strategist) taxa. While Spartobacteria (e.g., Ca. Udaeobacter) are typically oligotrophic, classes such as Opitutia and Verrucomicrobiae exhibit mixed strategies. Beyond nutrient cycling, several members of the phylum function as plant growth-promoting and stress mitigating bacteria. They produce phytohormones (e.g., indole-3-acetic acid) and siderophores, increase the availability of nitrogen and solubilise phosphate. Some taxa exhibit antioxidant activity and can suppress phytopathogens such as Fusarium oxysporum through secondary metabolite production. These traits suggest a significant potential in soil health improvement. Overall, Verrucomicrobiota represent a functionally diverse and ecologically significant bacterial phylum whose metabolic versatility, adaptive life strategies, and plant-associated traits underscore their central role in sustainable agricultural ecosystems.

RevDate: 2025-11-22

Zou H, Ying W, Mafla Endara PM, et al (2025)

Deep learning-driven investigation of nanoplastic impacts on soil protist behavior in soil chips.

Environmental pollution (Barking, Essex : 1987) pii:S0269-7491(25)01788-9 [Epub ahead of print].

Nanoplastics are emerging environmental contaminants that increasingly threaten soil ecosystems, yet their effects on microbial behavior remain poorly understood. This is mainly due to the lack of experimental tools capable of directly observing microbial dynamics in situ under realistic soil-like conditions. Here, we present a proof-of-concept system that enables real-time, high-throughput monitoring of soil protists within microfluidic soil chips under nanoplastic exposure. Using microscopy video analysis integrated with a deep learning-based detection model and a transformer-based trajectory reconstruction algorithm, we quantitatively measured the movement of morpho-/locomotion type groups flagellates, ciliates, and amoebae across a gradient of nanoplastic concentrations (0, 2, and 10 mg/L). Our results showed reduced movement velocities for the groups of flagellates and ciliates under high nanoplastic conditions with a 24%-30% reduction in speed, while affect on amoebae was not detected. The trajectory data also provides novel insights into how protists navigate soil-like structures. Beyond these specific findings, our approach establishes a transformative framework for observing microbial life directly in its microenvironment, comparable to how animal behavior is monitored in ecological studies. By bridging real-time imaging and artificial intelligence, this method offers a new angle to study protist-environment interactions without the need for culture extraction. It opens the door to rethinking how microbial ecology, soil contamination, and biotic responses to environmental stressors are investigated, advancing opportunities from static, population-level measurements to dynamic, behavioral-level understanding within realistic habitats.

RevDate: 2025-11-22

Wu YX, Wang HY, Chu WC, et al (2025)

Ecological implications of biodegradable and conventional microplastics: Dissolved organic matter bioavailability and microbial response in marine systems.

Journal of hazardous materials, 500:140526 pii:S0304-3894(25)03446-6 [Epub ahead of print].

The increasing accumulation of microplastics (MPs) in marine environments raises concerns about their ecological impacts, particularly through the release of dissolved organic matter (DOM). However, the bioavailability and ecological effects of MPs-derived DOM (MPs-DOM) remain poorly understood. In this study, we systematically investigated the leaching characteristics and microbial bioavailability of DOM derived from three biodegradable MPs (BMPs) including polylactic acid (PLA), polycaprolactone (PCL), polybutylene adipate terephthalate (PBAT) and two conventional MPs (CMPs, PE: polyethylene, PET: polyethylene terephthalate) under simulated photoaging. Our results demonstrated that BMPs released significantly more dissolved organic carbon (DOC) than CMPs, with PBAT showing the highest yield (40.77 vs. PE: 11.63 mg-DOC g-C[-1]). Optical analyses revealed that BMPs-DOM contained more protein-like fluorescent components, with higher fluorescence index and biological index, indicating greater lability. BMPs-DOM stimulated microbial growth more efficiently, with PBAT supporting the highest bacterial concentrations (∼52 ×10[3] cells mL[-1]) and DOC utilization (76.39 %). 16S rRNA sequencing revealed that MPs-DOM exposure reduced community richness, reshaped microbial communities through selective enrichment of copiotrophic and plastic-degrading taxa (e.g., Pseudomonas, Bacteroidota), and promoted stochastically driven assembly with specialized functional modules. Our study highlights that while BMPs may alleviate particulate plastic accumulation, their labile DOM release warrants careful evaluation for potential impacts on marine microbial ecology.

RevDate: 2025-11-22

Bi J, Li J, Rahman SU, et al (2025)

Balancing water efficiency and crop productivity: rhizosphere microbiome shifts in drought-resistant rice.

World journal of microbiology & biotechnology, 41(12):469.

RevDate: 2025-11-21

Khatbane M, Mangavel C, Borges F, et al (2025)

Knowledge graph embedding for predicting and analyzing microbial interactions.

Scientific reports pii:10.1038/s41598-025-27591-9 [Epub ahead of print].

Interactions between microorganisms play a major role in shaping the structure and function of microbial communities, yet their prediction remains a challenge in microbial ecology. While currently available machine learning methods have shown promising performance, they often rely on extensive input features that are obtained from labor-intensive experiments. Here, we propose a new framework to predict pairwise interactions that minimizes the need for in vitro experimentation. Our approach is based on knowledge graph embedding, which learns the representation of microorganisms and their interactions in an embedding space. Using a dataset of interactions between 20 soil bacterial strains cocultured in 40 different carbon source environments, we demonstrate the effectiveness of our framework in accurately predicting pairwise interactions. Notably, we show that our model can predict interactions involving strains with missing culture data. We additionally show that the obtained embeddings can reveal similarities between carbon source environments, enabling the prediction of interactions in one environment based on the outcomes in a similar environment between the same pair of microorganisms. Furthermore, our approach allows the design of a recommendation system that can be used to guide microbial community engineering. These findings demonstrate that knowledge graph embedding is a promising modeling strategy in microbial ecology.

RevDate: 2025-11-21

Man M, Castañeda-Gómez L, Moisan MA, et al (2025)

Deciphering the Complex Interactions between Litter Inputs and Microbial Responses in Modulating Long-Term Soil Organic Matter Dynamics.

Environmental science & technology [Epub ahead of print].

Natural climate solutions that focus on increasing carbon in forests rely on the potential for additional carbon that may be incorporated into soil organic matter (SOM). The fate of soil carbon in temperate forests remains uncertain due to the complex role of microbes and their regulation of carbon flows in soils, especially with the addition of extra litter. We identified comprehensive molecular-level evidence that revealed shifts in SOM composition and microbial communities after 30 years of added litter in a temperate deciduous forest. Chronic litter addition failed to add new soil carbon after 30 years and correlated with reorganization in microbial community composition and altered carbon use. Excluding detrital inputs decreased soil carbon content, resulting in enhanced SOM decomposition and shifts toward specific bacterial groups (such as oligotrophs) that can utilize less energetically favorable carbon substrates that are typically more recalcitrant. Collectively, we found that microbial communities shifted in composition and altered carbon use strategies and traits, which aligned with changes to the molecular composition of SOM. Finally, this work demonstrates that in mesic temperate forests, decadal increases in litterfall, resulting from increased ecosystem productivity or management, may not offset soil carbon losses from climate change nor enhance carbon sequestration.

RevDate: 2025-11-21
CmpDate: 2025-11-21

Madsusan A, Krainara S, Suksong W, et al (2025)

Impact of a tropical monsoon climate on formaldehyde exposure and microbial contamination in anatomy dissection hall.

PloS one, 20(11):e0337238 pii:PONE-D-25-25583.

Gross anatomy dissection is an essential component of medical and health science education, yet it presents notable occupational hazards, particularly from formaldehyde (FA) exposure and microbial contamination. These risks may be intensified in anatomy dissection halls located in tropical monsoon (Am) climates, where elevated humidity and temperature promote both chemical volatility and microbial persistence. This study assessed the combined effects of such climatic conditions on FA concentrations and microbial ecology within a naturally ventilated dissection hall in southern Thailand. FA levels were measured through personal and area air sampling across seven anatomical regions, while microbial contamination on cadaver-contact surfaces was evaluated using culture-based methods and high-throughput sequencing. Functional prediction of microbial communities was performed using PICRUSt2 to assess their metabolic adaptation to environmental stressors. The results revealed that both personal and indoor FA concentrations (mean 1.17 ± 0.39 ppm and 1.09 ± 0.45 ppm, respectively) exceeded several international occupational exposure limits, with the highest levels observed during dissections involving deep or adipose-rich anatomical regions. Microbial analyses identified stress-tolerant and potentially pathogenic genera, including Bdellovibrio, Aequorivita, and Aspergillus spp., along with enriched pathways involved in aromatic compound degradation and environmental resilience. These findings highlight the limitations of natural ventilation in controlling occupational exposures and microbial contamination in Am climate anatomy laboratories. The study supports the implementation of climate-responsive engineering controls and laboratory management strategies that address chemical safety, thermal regulation, and biosafety to promote healthier and more sustainable dissection environments in similar high-risk settings.

RevDate: 2025-11-21

Xin H, He L, B Zhu (2025)

Ecological Insights into Gut Microbiota Networks Across Cognitive States in Alzheimer's Disease.

Microbial ecology pii:10.1007/s00248-025-02662-6 [Epub ahead of print].

The ecological mechanisms governing gut microbial community stability during Alzheimer's disease (AD) progression remain poorly understood. This study employed an ecological network to investigate microbial interactions and stability across cognitively normal controls (CK), individuals with mild cognitive impairment (MCI), and AD patients. We observed a stepwise decline in network complexity across groups, characterized by reduced clustering coefficients and average degree, from CK to AD. While the MCI group exhibited intermediate structural complexity, it displayed the highest vulnerability and lowest robustness, indicating a critical transitional state. Keystone taxa analysis revealed a significant shift in microbial community, with the CK network was enriched with diverse, potentially beneficial keystone taxa, whereas the AD network retained only connector species, and the MCI network showed a complete absence of keystone taxa. Cohesion analysis revealed a non-linear trajectory of microbial interactions, with negative cohesion peaking in MCI. Our findings demonstrate that cognitive decline is associated with a fundamental reorganization of the gut microbial ecosystem. This reorganization pattern reveals a resilient state in health, a vulnerable phase in MCI, and a stable yet dysbiotic configuration in AD, with keystone taxa serving as pivotal regulators of community stability. Community assembly analysis showed a shift from deterministic to stochastic processes during cognitive decline, with weakened host regulatory mechanisms. These findings advance our understanding of the gut microbial ecology in neurodegenerative disease and reveal the mechanism by which microbial communities reorganize network to maintain stability in different cognitive states.

RevDate: 2025-11-21
CmpDate: 2025-11-21

Zhao Y, Zhao Y, Dong Y, et al (2025)

Biogeography of Virioplankton Abundance and Subcluster Patterns in the Northwest Pacific: A Large-Scale Perspective.

MicrobiologyOpen, 14(6):e70161.

Marine virioplankton, the most abundant biological entities in the ocean, play essential roles in microbial ecology and biogeochemical cycling. This study investigates their biogeography in the Northwest Pacific using enhanced-resolution flow cytometry and phenotypic diversity analyses. By resolving four consistent viral subclusters across oceanic and coastal waters and detecting a fifth subcluster in the Yellow Sea, we revealed previously unrecognized patterns of viral community structures. Viral abundances ranged from 3.69 × 10[6] to 17.09 × 10[6] particles/mL, showing clear coastal-oceanic differentiation. Environmental gradients, particularly temperature, chlorophyll, and picoplankton abundance, emerged as the primary drivers of virioplankton community structure. These findings underscored the tight coupling between viral populations and their microbial hosts across contrasting marine environments. Phenotypic diversity analysis revealed distinct viral communities in the Luzon Strait, despite comparable abundance patterns to adjacent regions, demonstrating the method's sensitivity in detecting subtle community shifts. This study advances understanding of marine viral biogeography and introduces a robust framework for investigating viral community dynamics. The approach enables high-throughput screening across large spatial scales while maintaining sensitivity to fine-scale community variations, offering new possibilities for monitoring viral responses to environmental change in marine ecosystems.

RevDate: 2025-11-21
CmpDate: 2025-11-21

Trivedi S, Roy R, Naskar A, et al (2025)

Cuminaldehyde Potentiates the Antimicrobial and Antibiofilm Activity of Vancomycin: A Biochemical Study to Manage the Threats of Methicillin Resistant Staphylococcus aureus (MRSA).

APMIS : acta pathologica, microbiologica, et immunologica Scandinavica, 133(11):e70087.

Methicillin-resistant Staphylococcus aureus (MRSA) is reported to cause serious health issues in humans by exploiting its biofilm network. To combat this global concern, the combined efficacy of cuminaldehyde (a bioactive phytochemical) and vancomycin (an antibiotic) was tested against MRSA strains. While both compounds exhibited independent antibacterial activity, their combination revealed improved efficacy against MRSA through additive interactions. Response surface methodology (RSM)-generated quadratic models optimized the combinatorial doses, revealing significant microbial growth inhibition of the MRSA strains (p < 0.05). Furthermore, the combined application of cuminaldehyde and vancomycin at sub-MIC doses could inhibit biofilm formation by lowering bacterial adhesion, extracellular polysaccharide (EP) synthesis and the extent of biofilm-associated proteins. Additionally, the mechanistic studies revealed that the said combination (cuminaldehyde and vancomycin) was found to accumulate oxidative stress with a ~2.5-fold increase in intracellular reactive oxygen species (ROS) and a ~2.3-fold reduction in membrane integrity. In view of the same, this combination attenuated key virulence factors (protease, hemolysin, and coagulase) and metabolic activity of MRSA. Hence, the combinations involving cuminaldehyde and vancomycin could potentially enhance the antimicrobial and antibiofilm efficacy, presenting a promising approach to combat the escalating crisis linked with MRSA-associated threats.

RevDate: 2025-11-21
CmpDate: 2025-11-21

Fu Y, Dou Q, Wang F, et al (2025)

A flowing database: Harnessing sewage-based surveillance for antimicrobial resistance.

Innovation (Cambridge (Mass.)), 6(11):100977.

RevDate: 2025-11-21

Sharma P, Dagariya S, Sharma S, et al (2025)

Uncovering the nexus of human health hazards of nanoplastics, gut-dysbiosis and antibiotic-resistance.

Journal of environmental science and health. Part C, Toxicology and carcinogenesis [Epub ahead of print].

Nanoplastics (1-1000 nm) (NPs) represent a novel and insidious class of emerging contaminants with the potential to profoundly disrupt gut microbial ecology and accelerate the spread of antibiotic resistance two critical and converging threats to global health. While prior studies have examined the toxicokinetics of NPs and their general microbial interactions, this review provides the first comprehensive synthesis specifically focused on the nexus between NPs, gut dysbiosis, and the propagation of antibiotic resistance genes (ARGs). This review highlights how NPs alter gut microbiota composition, suppressing beneficial microbes while fostering opportunistic pathogens and how such imbalances may contribute to human health issues. Importantly, emerging evidence also suggests that NPs may serve as unrecognized vectors for horizontal gene transfer (HGT), enabling the rapid dissemination of ARGs via conjugation, transformation, transduction, and extracellular vesicles within the gastrointestinal tract. In addition, this review also identifies urgent methodological gaps in detecting NPs in biological matrices and the environment, as well as assessing their mechanistic impacts, calling for innovation in analytical approaches. By presenting an interdisciplinary perspective that bridges nanotoxicology, microbiome science, and antimicrobial resistance, this article sheds light on an underexplored yet urgent frontier in environmental health, offering novel insights to guide future research, risk assessment, and policy development.

RevDate: 2025-11-20

Hu H, Zhang Y, Liu Z, et al (2025)

Microbial Diversity Affects the Cold Tolerance of Red Swamp Crayfish (Procambarus clarkii) by Regulating Histamine Metabolism.

Microbial ecology pii:10.1007/s00248-025-02659-1 [Epub ahead of print].

The red swamp crayfish (Procambarus clarkii) is one of the important freshwater aquaculture species in China, but its growth and development are greatly affected by temperature, which makes it difficult to expand its aquaculture range to the northern regions of China. The composition of gut microbes plays a vital role in resisting environmental pressure, and is also an important driving factor for amino acid metabolism in the body. However, little is known about the relationship between microorganisms, metabolism, and cold-resistance ability of P. clarkii. In this study, we performed the cold-resistance and antioxidant ability test, gut microbiota diversity analysis, quantitative analysis of histamine, and bioinformatics analysis of histamine receptor (HR) family on P. clarkii. The results showed that the cold-resistance crayfish exhibited high antioxidant ability and low gut microbiota diversity after acute cold stress. Next, we also found that there was significant correlation between the Lactobacilli genus and histamine abundance, indicating that the excellent cold tolerance ability of crayfish may stem from the degradation of histamine by Lactobacilli. Finally, it was revealed that HR genes had considerable quantity of gene copies, conservative evolution in crustacean lineages and expression differences in low-temperature tolerant populations. These results suggested that the diversity of Lactobacillus mediated changes in histamine metabolism affect antioxidant capacity, which is one of the reasons why P. clarkii exhibits cold resistance ability. This finding provided a theoretical basis for understanding the microorganism-histamine regulation mechanism of red swamp crayfish under cold stress, promoting the breeding and healthy culture of cold-resistance strain.

RevDate: 2025-11-20

Caroppo C, Caruso G, Bergamasco A, et al (2025)

Phytoplankton diversity and size structure in the Central-Southern Tyrrhenian Sea: implications for microbial functioning.

Microbial ecology pii:10.1007/s00248-025-02650-w [Epub ahead of print].

Microbial community dynamics in relation to mesoscale hydrographical features are almost unknown particularly in the pelagic Central-Southern Tyrrhenian Sea. To get a more comprehensive view of phytoplankton community structure and microbial community functioning, datasets of phytoplankton abundance, composition and some microbial enzyme activities (leucine aminopeptidase, LAP, beta-glucosidase, GLU and alkaline phosphatase, AP) from six cruises carried out twenty years ago were analyzed. Hydrographic characteristics identified the presence of both Atlantic Waters (AW) and Tyrrhenian Intermediate Waters (TIW). Size structure of phytoplankton biomass showed an unexpected high contribution of the pico-phytoplankton to the total primary production (> 60%) determining a predominant microbial food web. Phytoplankton distribution patterns varied more significantly on a seasonal rather than spatial scale. Autumn assemblages were characterized by the highest abundance and carbon content, with species mainly belonging to dinoflagellates whose growth was supported by intense microbial activities. In contrast, in the summer diatoms developed in unstable TIW where microbial activity was declining. Enzymatic activities varied in the different water masses and seasons, with high LAP activity in summer AW (s-AW) as well as in deep TIW (d-TIW), while AP and GLU reached their maximum in autumn AW (a-AW), suggesting quick organic matter recycling. Coupled primary production and hydrolysis in mixed AW (m-AW) and in a-AW indicated synchronized autotrophic and heterotrophic processes, while in TIW organic matter was only partially recycled. Overall, microbial metabolism was closely shaped by hydrographic and seasonal dynamics, confirming its key role in biogeochemical cycles. Our data could provide a baseline study for future research dealing with the microbial functioning in this Mediterranean region.

RevDate: 2025-11-21
CmpDate: 2025-11-21

Tucker SJ, Freel KC, Eren AM, et al (2025)

Habitat-specificity in SAR11 is associated with a few genes under high selection.

The ISME journal, 19(1):.

The order Pelagibacterales (SAR11) is the most abundant group of heterotrophic bacteria in the global surface ocean, where individual sublineages likely play distinct roles in oceanic biogeochemical cycles. Yet, understanding the determinants of niche-partitioning within SAR11 has been a formidable challenge due to the high genetic diversity within individual SAR11 sublineages and the limited availability of high-quality genomes from both cultivation and metagenomic reconstruction. Through an integrated metapangenomic analysis of 71 new SAR11 isolate genomes and a time-series of metagenomes from the prominent source of isolation, we reveal an ecological and phylogenetic partitioning of metabolic traits across SAR11 genera. We resolve distinct habitat-preferences among genera for coastal or offshore environments of the tropical Pacific and identify a handful of genes involved in carbon and nitrogen metabolisms that appear to contribute to these contrasting lifestyles. Furthermore, we find that some habitat-specific genes experience high selective pressures, indicating that they are critical determinants of SAR11 fitness and niche differentiation. Together, these insights reveal the underlying evolutionary processes shaping niche-partitioning within sympatric and parapatric populations of SAR11 and demonstrate that the immense genomic diversity of SAR11 bacteria naturally segregates into ecologically and genetically cohesive units, or ecotypes, that vary in spatial distributions in the tropical Pacific.

RevDate: 2025-11-20

Mol Z, Segers L, Van Langenhove H, et al (2025)

Pressure-induced taste and odour deviations within the high-pressure drinking water distribution system.

Water research, 289(Pt B):124965 pii:S0043-1354(25)01868-8 [Epub ahead of print].

Taste and odour (T&O) issues in tap water decrease the willingness of consumers to drink it. Production and/or release of odour compounds during drinking water distribution should be avoided as the water is directly delivered to consumers without further treatment. Odours can be caused by leaching of compounds from pipe materials, microbial metabolism, disinfection reactions, or diffusion of odour compounds or precursors from external sources. Increasing knowledge of T&O origins is needed to better solve future problems. Therefore, this research focuses on odour linked to changes in pressure because of maintenance work at the high-pressure (HP) drinking water distribution system. A trace analytical method targeting 45 T&O compounds is further optimized by including derivatisation to improve halophenol detection. Next, in a field section of a real HP pipe (± 3 km), three scenarios were systematically investigated. Lowering the overpressure in the HP pipe from 10 to 5 bar resulted in an observed bitumen/asphalt odour, that further increased in intensity after a subsequent sudden pressure drop to 2 bar. Based on the odour threshold and profile, two halophenols were detected that may have contributed to this odour observation. When the section was partially emptied, 6 halophenols and 5 other T&O compounds were identified. Our results indicate that pressure changes induce the leaching of T&O compounds from sealing materials connecting the 6m-pipe sections. This is further supported by the detection of similar T&O compounds in a water extract of the sealing materials and in an odorous household sample collected after maintenance work in the HP-network.

RevDate: 2025-11-20

Yang C, Bao L, Shi Z, et al (2025)

Jingning formula alleviates ADHD by restoring gut microbiota dysbiosis and tryptophan metabolic dysfunction.

Journal of pharmaceutical and biomedical analysis, 269:117256 pii:S0731-7085(25)00597-7 [Epub ahead of print].

Jingning Fang (JNF), a clinically used herbal medicine for attention deficit hyperactivity disorder (ADHD), demonstrates significant efficacy in alleviating core symptoms such as hyperactivity and impulsivity in pediatric patients. To systematically investigate its therapeutic mechanisms, we implemented an integrated approach encompassing UPLC-Q-TOF/MS-based untargeted metabolomics profiling of brain, serum, and fecal specimens, targeted quantification of tryptophan pathway metabolites across these biological compartments, and gut microbiome characterization via 16S rRNA sequencing. Our analysis revealed a prominently dysregulated metabolic pathway in ADHD, characterized by perturbations in tryptophan metabolism that were particularly pronounced in feces (P < 0.05). Notably, the kynurenic acid (KYNA)/quinolinic acid (QUINA) ratio, a pivotal indicator of kynurenine pathway homeostasis, exhibited robust correlations with both behavioral manifestations and gut microbial ecology. These findings provide a mechanistic basis for JNF's clinical efficacy in ADHD management by highlighting its role in restoring gut microbiome balance and tryptophan metabolic homeostasis.

RevDate: 2025-11-20

Kosmopoulos JC, K Anantharaman (2025)

Viral Dark Matter: Illuminating Protein Function, Ecology, and Biotechnological Promises.

Biochemistry [Epub ahead of print].

Viruses are the most abundant biological entities on Earth and play central roles in shaping microbiomes and influencing ecosystem functions. Yet, most viral genes remain uncharacterized, comprising what is commonly referred to as "viral dark matter." Metagenomic studies across diverse environments consistently show that 40-90% of viral genes lack known homologues or annotated functions. This persistent knowledge gap limits our ability to interpret viral sequence data, understand virus-host interactions, and assess the ecological or applied significance of viral genes. Among the most intriguing components of viral dark matter are auxiliary viral genes (AVGs), including auxiliary metabolic genes (AMGs), regulatory genes (AReGs), and host-physiology-modifying genes (APGs), which may alter host function during infection and contribute to microbial metabolism, stress tolerance, or resistance. In this Review, we explore recent advances in the discovery and functional characterization of viral dark matter. We highlight representative examples of novel viral proteins across diverse ecosystems, including human microbiomes, soil, oceans, and extreme environments, and discuss what is known and still unknown about their roles. We then examine the bioinformatic and experimental challenges that hinder functional characterization and present emerging strategies to overcome these barriers. Finally, we highlight both the fundamental and applied benefits that multidisciplinary efforts to characterize viral proteins can bring. By integrating computational predictions with experimental validation and fostering collaboration across disciplines, we emphasize that illuminating viral dark matter is both feasible and essential for advancing microbial ecology and unlocking new tools for biotechnology.

RevDate: 2025-11-20

Villalón A, Rodríguez Alonso Á, Carballo J, et al (2025)

Diversity of Bacteria and Yeasts Present in an Automobile Treatment System.

Microbial ecology pii:10.1007/s00248-025-02651-9 [Epub ahead of print].

The formation of biofilms in industrial environments poses a significant challenge because of their ability to degrade materials, contaminate products, and harbour pathogenic microorganisms. In the automotive industry, surface treatment systems (STS) used to prepare car bodies can provide a favourable environment for microbial development, driven by the presence of water, organic matter, and variable physicochemical conditions. In this context, the microbial diversity present in the different STS baths of an automotive plant, as well as in the process water, was analysed. Through culture-based methods and molecular analysis, 33 bacterial and 6 yeast species were identified. The results revealed a constant presence of bacteria at all sampling points, whereas yeasts were detected less frequently and in more localized areas (Industrial and Dechromatized Water, E2, Conversion stage, E4 and Passivation stage). This study underscores the importance to enhance cleaning and disinfection protocols in STS, as high bacterial counts persisted even after rinsing stages, in order to prevent economic losses, product degradation and health risks. Furthermore, it highlights the potential use of certain microorganisms in biotechnology and bioremediation applications.

RevDate: 2025-11-20

Ding W, Ling Z, Liu X, et al (2025)

Impact of carbapenem-resistant Klebsiella pneumoniae infection on gut microbiota and host immunity: a case-control study.

Microbiology spectrum [Epub ahead of print].

Carbapenem-resistant Klebsiella pneumoniae (CRKP) represents a critical global health threat with limited treatment options. While the gut microbiota is a reservoir for opportunistic pathogens and a regulator of host immunity, the reciprocal impact of systemic CRKP infection on gut microbial ecology and immune responses remains poorly defined. In a prospective case-control study, 38 patients with confirmed CRKP infection and 38 matched hospitalized controls without CRKP were enrolled. Fecal samples underwent 16S rRNA gene sequencing to characterize microbial profiles, and serum cytokine levels were quantified using multiplex immunoassays. CRKP infection was associated with significantly reduced microbial diversity and a distinct shift in community structure, characterized by depletion of beneficial commensals (Bacteroides, Faecalibacterium, Roseburia) and enrichment of pathobionts (Klebsiella, Enterococcus). Enterotype analysis revealed a predominance of a Klebsiella/Enterococcus-dominated enterotype in CRKP patients. Functional predictions indicated impaired carbohydrate and butyrate metabolism alongside increased virulence- and resistance-associated pathways. Systemically, patients exhibited elevated pro-inflammatory cytokines (IL-6, TNF-α, IFN-γ) and chemokines (IP-10, MCP-1, RANTES). Correlation analyses linked opportunistic taxa with heightened inflammatory markers, while beneficial short-chain fatty acid producers showed inverse associations. Systemic CRKP infection is associated with profound gut dysbiosis and a hyper-inflammatory immune response. The strong microbiota-immune correlations suggest that the gut microbiota may serve as a biomarker and a potential therapeutic target for mitigating CRKP-associated immune dysfunction, though the directional relationship (cause vs. consequence) between dysbiosis and CRKP infection remains to be elucidated.IMPORTANCECarbapenem-resistant Klebsiella pneumoniae (CRKP) is a critical global threat with limited therapeutic options. This study reveals that systemic CRKP infection is associated with profound gut dysbiosis-characterized by loss of beneficial commensals (e.g., Faecalibacterium) and expansion of pathobionts (e.g., Klebsiella, Enterococcus)-as well as a hyperinflammatory immune response. We demonstrate strong correlations between specific microbial taxa and host cytokines, suggesting that the gut microbiome may hold potential as a biomarker and therapeutic target. These findings enhance our understanding of host-microbe interactions in CRKP infection and support the exploration of microbiota-based therapies. However, further studies, including longitudinal and animal models, are needed to clarify whether gut dysbiosis directly influences CRKP outcomes or is a secondary consequence.

RevDate: 2025-11-20

Gilbert JA, Scholz AH, Dominguez Bello MG, et al (2025)

Safeguarding microbial biodiversity: microbial conservation specialist group within the species survival commission of the International Union for Conservation of Nature.

The ISME journal, 19(1):.

RevDate: 2025-11-20

Gilbert JA, Scholz AH, Dominguez Bello MG, et al (2025)

Safeguarding microbial biodiversity: microbial conservation specialist group within the species survival commission of the International Union for Conservation of Nature.

FEMS microbiology ecology, 101(12):.

RevDate: 2025-11-20

Gilbert JA, Scholz AH, Dominguez Bello MG, et al (2025)

Safeguarding microbial biodiversity: microbial conservation specialist group within the species survival commission of the International Union for Conservation of Nature.

RevDate: 2025-11-20
CmpDate: 2025-11-20

Postec A, Yumoto I, Morales-Barrera L, et al (2025)

Editorial: Microbial ecology and biotechnological potential of alkaline environments.

Frontiers in microbiology, 16:1726999.

RevDate: 2025-11-20
CmpDate: 2025-11-20

Bautista J, A López-Cortés (2025)

Chronobiome medicine: circadian regulation of host-microbiota crosstalk in systemic physiology.

Frontiers in endocrinology, 16:1691172.

Circadian rhythms, governed by central and peripheral clocks, orchestrate nearly all aspects of human physiology, including metabolism, endocrine function, neuroimmune activity, and behavior. Emerging evidence reveals that these oscillations are closely intertwined with the gut microbiota, which itself displays diurnal fluctuations in composition and metabolite production. This bidirectional regulation establishes a dynamic circadian-microbiota axis that synchronizes nutrient processing, hormonal secretion, immune surveillance, and neural signaling. Disruption of this temporal alignment, through genetic, environmental, or lifestyle factors, precipitates systemic dysregulation, fostering metabolic syndrome, endocrine imbalance, immune dysfunction, neuropsychiatric vulnerability, cardiovascular alterations, and carcinogenesis. Mechanistic studies highlight that microbial-derived metabolites such as short-chain fatty acids, bile acids, and indoles act as circadian cues, while host clock genes modulate microbial ecology and intestinal barrier integrity. These insights underscore the translational potential of circadian precision medicine, in which time-restricted feeding, probiotics, prebiotics, and chronotherapy restore synchrony between microbial and host clocks. This review synthesizes current knowledge on circadian modulation of microbiota-mediated crosstalk across metabolic, neural, immune, and endocrine pathways, emphasizing its implications for health, disease, and novel therapeutic strategies.

RevDate: 2025-11-19

Zhang Q, Zhang S, Cao X, et al (2025)

The gut microbiota in post-stroke depression: A systematic review of microbial mechanisms and therapeutic targeting of neuroinflammation.

Microbiological research, 303:128391 pii:S0944-5013(25)00350-7 [Epub ahead of print].

Post-stroke depression (PSD), a frequent and debilitating complication after stroke, severely hinders rehabilitation. Emerging evidence underscores the role of neuroinflammation and the gut microbiota in PSD pathogenesis. This review systematically elaborates the mechanisms by which gut dysbiosis contributes to PSD-related neuroinflammation via immune cell regulation (e.g., Treg/Th17 balance), microbial metabolites (e.g., SCFAs, tryptophan derivatives), and neural pathways (vagus nerve, HPA axis). A key focus is the comparative analysis of the gut microbiota in PSD against major depressive disorder (MDD) and Alzheimer's disease (AD), revealing a unique, stroke-induced microbial signature characterized by a loss of protective symbionts and a bloom of pro-inflammatory taxa. We further discuss the translational potential of microbiota-targeted interventions (e.g., probiotics, prebiotics) for PSD. By integrating clinical microbial ecology with mechanistic insights, this review synthesizes evidence suggesting that the gut microbiome may represent a promising diagnostic and therapeutic target for PSD, offering a distinct perspective from previous literature.

RevDate: 2025-11-19

Yang W, X Wang (2025)

Transmission mechanisms and risk tracing of antibiotic resistance genes in rivers driven by wastewater inputs.

Journal of hazardous materials, 500:140523 pii:S0304-3894(25)03443-0 [Epub ahead of print].

Aquatic environments are critical for ARG dissemination, yet contributions from different wastewater sources, dominant HGT mechanisms, and residual risks in natural waters remain unclear. Based on 863 metagenomic samples across China, we systematically analyzed wastewater inputs, HGT mechanisms, and risks of riverine ARGs. Wastewater treatment plants were the primary source, contributing about 50 % of riverine ARGs. Conjugation dominated ARG transfer, primarily via F-type type IV secretion systems. High-transmission plasmids were widespread. Although phage-mediated transduction represented only 3 % of HGT, it facilitated cross-environmental spread of clinically significant blaGES-18. Metagenome-assembled genomes revealed 78 % of resistant bacteria belonged to Pseudomonadota; 42 % co-harbored virulence factors. Phylogenetic analysis showed high inter-generic mobility of sul1/sul2, explaining their environmental persistence. Overall risk in rivers decreased by 44 % - 93 % compared to wastewaters. However, Acinetobacter carrying blaOXA and Cellvibrio sp002483145 carrying blaKHM-1 were phylogenetically close to Acinetobacter baumannii and Pseudomonas aeruginosa, indicating potential pathways toward key pathogens. Our study identifies wastewater as the main source of riverine ARGs, reveals conjugation as the primary transmission mechanism with transduction playing a secondary role, and demonstrates that high-risk ARGs can still spread to pathogenic bacteria in rivers. These findings are crucial for developing effective strategies to mitigate ARG risks.

RevDate: 2025-11-19
CmpDate: 2025-11-19

Usman H, Molaei M, House SD, et al (2025)

Magnetically responsive nanocultures for direct microbial assessment in soil environments.

Science advances, 11(47):eady2654.

Cultivating microorganisms in native-like conditions is vital for bioprospecting and accessing now unculturable species. However, there remains a gap in scalable tools that can both mimic native microenvironments and enable targeted recovery of microbes from complex settings. Such approaches are essential to advance our understanding of microbial ecology, predict community functions, and discover previously unidentified biotherapeutics. We present magnetic nanocultures-a high-throughput microsystem for isolating and growing environmental microbes under near-native conditions. These nanoliter-scale bioreactors are encapsulated in semipermeable membranes that form magnetic polymeric microcapsules using iron oxide nanoparticles within polydimethylsiloxane-based shells. This design offers mechanical stability and magnetic actuation, enabling efficient retrieval from soil-like environments. The nanocultures are optimized for optical and biological properties to support microbial encapsulation, growth, and sorting. Our study demonstrates the feasibility of using magnetically responsive microenvironments to cultivate elusive microbes, offering a promising platform for bioprospecting previously uncultured or unknown microbial species.

RevDate: 2025-11-19

Marsh CC, Nel Van Zyl K, Babalola OO, et al (2025)

From description to implementation: key takeaways from the 3rd African Microbiome Symposium.

mSphere [Epub ahead of print].

The 3rd African Microbiome Symposium was held in Cape Town, South Africa, from 20 to 22 November 2024. The symposium featured a diverse range of local and international microbiome research and provided a platform for 79 researchers, students, and industry members to engage in discussions on the microbiome within an African context and focusing on translational research. This meeting review shares highlights, findings, and recommendations derived from the event. Insights from two panel discussions revealed key barriers to microbiome research in Africa, including limited funding, infrastructure gaps, and a shortage of trained local scientists. Recommendations centered on increased investment, institutional training, adherence to ethical guidelines, and the fostering of equitable global partnerships.

RevDate: 2025-11-19

Cong D, Liu J, Yu S, et al (2025)

Assessment of Anthropogenic Impacts on Water Quality and Microbial Communities in the Heilongjiang Maolan Gou National Nature Reserve.

Microbial ecology pii:10.1007/s00248-025-02645-7 [Epub ahead of print].

Freshwater ecosystems within protected areas play a vital role in maintaining biodiversity and ecological stability, yet they are increasingly threatened by anthropogenic disturbances such as agriculture and tourism. Understanding the impacts of human activities on water quality and microbial community dynamics is essential for the effective conservation and management. This study investigates the spatial variability of water quality and microbial communities across the core, buffer, and experimental zones of the Heilongjiang Maolan Gou National Nature Reserve. Twelve water samples were collected and analyzed for key physicochemical parameters (turbidity, electrical conductivity (EC), chemical oxygen demand (COD), biochemical oxygen demand (BOD), NH4[+], PO4[3-] and heavy metals). The core zone exhibited excellent water quality with low turbidity (0.4-0.5 NTU), EC (45-130 µS/cm), COD (8-10 mg/L), BOD (1.5-2.2 mg/L). In contrast, the experimental zone showed significant contamination due to agriculture and tourism, with high COD (up to 35 mg/L), BOD (up to 6.5 mg/L), NH4[+] (0.18-0.35 mg/L), and PO4[3-] (0.008-0.035 mg/L). Heavy metal concentrations, particularly Cd (up to 0.24 µg/L), were elevated in the experimental zone, correlating with higher Pollution and Water Quality Indices (HPI up to 96.4, WQI up to 61.28). According to standard classifications, HPI values > 100 indicated heavy pollution and WQI scores between 50 and 100 denoted moderate to poor water quality, highlighting degraded conditions in the experimental zone. Microbial analysis revealed distinct community structures across zones, with enhanced pollutant-degrading taxa such as Pseudomonas (noted for aromatic hydrocarbon degradation) and members of Bacteroidota (associated with organic matter breakdown) in the experimental zone. These findings highlight the need for sustainable management to mitigate human impacts and preserve ecological health within the reserve.

RevDate: 2025-11-19

Gutiérrez-Sarmiento W, Fosado-Mendoza M, Lozano-Flores C, et al (2025)

The Body Wall Microbiome of the Terrestrial Slug Deroceras laeve Reveals Potential Endosymbionts and Shares Core Organisms with Other Mollusks.

Microbial ecology pii:10.1007/s00248-025-02652-8 [Epub ahead of print].

The marsh slug Deroceras laeve is an invasive mollusk found in gardens, field crops, and wetlands. It lacks a protective shell, suggesting that microbial communities are associated with its adaptability to the environment. Here, we used a whole shotgun metagenomic approach to analyse the complex microbiome of D. laeve and compared it to that of other mollusks. This demonstrated the presence in D. laeve of bacteriophages such as Erwinia phage, Certrevirus, and Machinavirus, which target plant pathogen bacteria. In the Archaea domain the halophilics Halovivax and Halobaculum predominated, but also present were the methanogens Methanobacterium, Methanobrevibacter, Methanocaldococcus, Methanococcus, and Methanosarcina, involved in phosphate solubilization and methanogenesis during decomposition of organic matter. The Bacteria domain was dominated by γ-Pseudomonadota such as Buttiauxella, Citrobacter, Enterobacter, Klebsiella, Kluyvera, Leclercia, and Pseudomonas which are producers of enzymes that degrade biomass and complex carbohydrates. Regarding the fungal community, filamentous or yeast ascomycetes predominated such as Debaryomyces, Puccina, and Pyricularia known as plant pathogens or associated with decaying organic matter. Consistent with these findings, functional analysis revealed enrichment in genes involved in fermentation and carbohydrate metabolism. Remarkably, regardless of species, ecosystem, and tissue type, we found that the core microbiome of the mollusks in this study is mainly structured by the Phyla Uroviricota, Euryarchaeaota, Pseudomonadota, and Ascomycota, with diversity at the genus level. This suggests ancient symbiotic interactions of these mollusks with specific types of microbes which may have been critical for adaptability to their environment.

RevDate: 2025-11-19

Romaní AM, Núria P, Marta P, et al (2025)

Drought Drives Extracellular Polymeric Substances Accumulation and Functional Shifts in Streambed Biofilm Communities.

Microbial ecology pii:10.1007/s00248-025-02649-3 [Epub ahead of print].

This study investigates the adaptive response of streambed microbial biofilms to water scarcity, focusing on the role of extracellular polymeric substances (EPS) production across a gradient of hydrological conditions. Sediment samples from 37 streams in the north-eastern Iberian Peninsula, encompassing both permanent and intermittent flow regimes, were analysed for EPS-polysaccharide content, microbial biomass, chlorophyll-a, and biofilm function (carbon substrate utilization profiles). Drought conditions were characterized based on the number of dry days over the eight months preceding sampling. Results revealed that EPS production increased significantly in intermittent streams, particularly under long-term drought, reaffirming that EPS synthesis is a key microbial strategy to mitigate desiccation stress. Notably, when normalized to prokaryotic density, EPS content exhibited a significant positive correlation with drought duration, emphasizing the dominant role of heterotrophic bacteria over algae in EPS secretion. However, EPS content alone was not a universal indicator of water scarcity, which showed a large variability in permanently flowing streams. Functional profiling showed clear shifts in carbon substrate utilization associated with stream hydrology. Intermittent streams exhibited a broader metabolic range, and particularly a capacity to use phenolic compounds, suggesting an adaptation to terrestrial organic matter inputs. Contrary to expectations, functional diversity increased in drier conditions, challenging assumptions derived from controlled experiments and underscoring the resilience of Mediterranean microbial biofilm communities to drought. These findings provide empirical support for EPS-mediated drought adaptation in natural biofilms and highlight functional diversity as a potential mechanism maintaining ecosystem processes under increasing aridity due to climate change.

RevDate: 2025-11-19

Cabrerizo MJ, González-Olalla JM, Medina-Sánchez JM, et al (2025)

Warming Fluctuations Strengthen the Photo-Phagotrophic Coupling in Mixoplanktonic Protists.

Microbial ecology pii:10.1007/s00248-025-02658-2 [Epub ahead of print].

Mixoplankton, a major trophic group in aquatic ecosystems, are being affected by global warming. However, most studies on temperature effects use constant mean conditions, overlooking how short-term thermal fluctuations could deviate from climate projections and impact this group. We experimentally quantified how increasing amplitudes of warming fluctuation (± 1, 3, and 5 °C) alter carbon-specific electron transport (ETR[c]), net photosynthesis (P[c]), respiration (R[c]), phagotrophy (Ph[c]), carbon use efficiency (CUE), and growth (µ) in four protist species (three mixoplanktonic and one strict phototroph). We observed a consistent positive link between photosynthetic efficiency (P[c]:ETR[c] ratio) and Ph[c], and a shift towards a strengthening of the Ph[c] (P[c]:ETR[c] / Ph[c] ratio) with greater thermal fluctuation. A potential explanation is a selective behavior aimed to increase phagotrophy to obtain inorganic nutrients through ingested prey internal re-cycling rather than relying on the environment, to support an enhanced photosynthetic efficiency and growth. An enhanced, coupled photo-phagotrophy activity could boost mixoplankton competitiveness compared to phytoplankton. Our findings underscore the need to incorporate trophic flexibility and its interaction with environmental variability into trait-based models to better predict community dynamics, biogeochemical cycling, and food web structure in aquatic ecosystems.

RevDate: 2025-11-19
CmpDate: 2025-11-19

Alster CJ, Schipper LA, E Bååth (2025)

Thermal Adaptation of Bacterial and Fungal Growth in a Geothermally Influenced Soil Transect.

Global change biology, 31(11):e70605.

Numerous studies have investigated microbial adaptation to increasing soil temperature, but limitations in experimental design hinder comprehensive understanding. These include short-term laboratory studies with constant environmental conditions and field studies with few distinct temperature treatments. Here, we utilized a long-term natural soil geothermal gradient in Aotearoa, New Zealand, ranging in mean annual soil temperature (MAT) from 17°C to 42°C to explore thermal adaptation of microbial growth rates. We collected soil from 28 locations along the gradient and measured bacterial growth rate (via leucine incorporation) at eight temperatures (4°C-45°C) and fungal growth rate (via Ac-in-ergosterol) at two temperatures (16°C and 39°C). We then fit Macromolecular Rate Theory and the Ratkowsky equation to estimate the temperature minimum (T min $$ {T}_{min} $$), optimum (T opt $$ {T}_{opt} $$), and inflection point (T inf $$ {T}_{inf} $$) for bacterial growth, and a temperature sensitivity index to compare relative fungal and bacterial growth rates. We found predictable changes in thermal adaptation of bacterial growth along the geothermal gradient with temperature response curves shifting 0.22°C-0.27°C per 1°C increase in MAT regardless of the temperature metric (i.e., T min $$ {T}_{min} $$ , T opt $$ {T}_{opt} $$ , and T inf $$ {T}_{inf} $$) used. Thermal adaptation of bacterial and fungal growth increased roughly in parallel. We also compared the bacterial growth results to published temperature response data of microbial respiration (with added glucose) from this geothermal gradient. Rates of thermal adaptation for bacterial growth and microbial respiration were similar, suggesting synchronicity across microbial processes. The less than 1°C change in all measured temperatures metrics per degree increase in MAT resulted in microbial growth and activity closer to in situ temperatures at high soil temperatures and lower than in situ temperatures under non-elevated soil temperatures. Overall, our results highlight the use of geothermal gradients and appropriate temperature models in studying thermal adaptation of soil microbial processes; the predictability of results also underscores potential for incorporating microbial thermal adaptation into soil carbon modeling efforts.

RevDate: 2025-11-18

Distante A, Garino D, Cerrato C, et al (2025)

The role of the human microbiome in prostate cancer: a systematic review from diagnosis to treatment.

Prostate cancer and prostatic diseases [Epub ahead of print].

BACKGROUND: Prostate cancer (PC) heterogeneity and treatment resistance remain major clinical challenges, with emerging evidence implicating the microbiome as a key modulator of disease pathogenesis. While microbial dysbiosis has been linked to PC diagnosis, progression, and therapeutic outcomes, the mechanisms underlying these associations are poorly understood. This review synthesizes current evidence on the diagnostic, prognostic, and therapeutic potential of the microbiome in PC.

METHODS: A systematic search of PubMed, Embase, and Cochrane Central Register of Controlled Trials (through April 2024) was conducted following PRISMA guidelines (PROSPERO: CRD42024534899). Controlled and observational studies investigating microbial roles in PC diagnosis (e.g., ISUP grading group), prognosis, or treatment response were included. Data extraction and quality assessment used the QUIPS tool. From 810 screened records, 42 studies met inclusion criteria.

RESULTS: Distinct microbial profiles differentiated PC from controls, with Mycoplasma genitalium and Staphylococcus spp. enriched in prostate tumors (3.1- and 2.7-fold, respectively) and correlated with inflammation (IL-6: r = 0.38, p = 0.002). Urinary microbiota showed diagnostic potential (sensitivity: 58-82%), though sampling methods influenced variability. Prognostically, Betaproteobacteria gut enrichment predicted earlier castration-resistant progression (5.2 months; HR 1.8, 95% CI 1.3-2.5), while ADT-induced dysbiosis (e.g., Klebsiella overgrowth) accelerated resistance (2.1-fold risk). Therapies altered microbial ecology: radiotherapy depleted Bacteroides (linked to proctitis; OR 3.1), and immunotherapy responders harbored higher Akkermansia muciniphila. Microbial androgen synthesis and endotoxin production emerged as resistance mechanisms.

CONCLUSIONS: The microbiome influences PC detection, aggressiveness, and treatment efficacy through direct (tissue-resident) and indirect (gut-derived) mechanisms. Standardized profiling and microbiome-modulating strategies (e.g., probiotics during ADT) may personalize management. Prospective trials are needed to validate causality and translate microbial biomarkers into clinical practice.

RevDate: 2025-11-18

Chen X, Huang Y, Zhu X, et al (2025)

Global biogeographic patterns and assembly processes of landfill leachate microbiomes.

Water research, 289(Pt B):124922 pii:S0043-1354(25)01825-1 [Epub ahead of print].

Approximately 95 % of municipal solid waste is disposed of in landfill globally, generating leachate that is known as a complex mixture of biodegradable and persistent toxic compounds. Microbes are main forces for tackling the toxic leachate but the patterns of microbial assembly in such treatments are largely unknown, limiting the proper optimization of leachate treatment efficiency. This study, for the first time, presents a global-scale analysis involving 151 landfill leachate treatment samples for uncovering mechanisms of microbial assembly from an ecological perspective. The information of microbiome from 97 treatments in Asia, 41 treatments in Europe, and 13 treatments in North America were collected. The results revealed pronounced biogeographic divergence, with Asian samples (particularly those from India) exhibiting lower microbial diversity and richness compared to Europe and North America counterparts. Geographical-climatic and socio-economic factors significantly influenced microbial composition, with elevation and per capita GDP being primary drivers. Further, the community assembly was predominantly governed by deterministic processes. Co-occurrence network analyses demonstrated distinct microbial interaction patterns across continents, with Asian networks being more vulnerable to collapse under external disturbances. This study provides critical insights into the global microbial ecology of landfill leachate treatment, offering a foundation for developing targeted bioremediation strategies.

RevDate: 2025-11-18
CmpDate: 2025-11-18

Della Mónica IF, Godeas AM, JM Scervino (2025)

Hyphosphere interactions: P-solubilizing fungi modulate AMF phosphatase activity and mycorrhizal symbiosis via exudate-mediated communication.

Mycorrhiza, 35(6):66.

Arbuscular mycorrhizal fungi (AMF) form symbiotic associations with plant roots, enhancing water and nutrient absorption. Phosphate-solubilizing fungi (PSF) can solubilize and mineralize phosphorus, an essential nutrient with low bioavailability, and eventually interact with AMF. However, the understanding of how they interact in the hyphosphere, where root influence is absent, remains limited. Furthermore, the effect of PSF on the phosphatase activity of AMF, related to the P efficiency in acquisition and utilization, within the hyphosphere and mycorrhizosphere zones, remains unclear. Therefore, this study aimed to assess the effect of three different PSF (Talaromyces flavus, T. helicus, and T. diversus) exudates on extracellular acid phosphatases and alkaline phosphatases associated with intra- and extraradical AMF structures in the hyphosphere and mycorrhizosphere, in vitro. To achieve this aim, the AMF Rhizophagus intraradices was cultured with Ri T-DNA transformed carrot roots in a system using Petri dishes that mimicked the hyphosphere (with 2 sections: (a) with roots and AMF, and (b) with only AMF) and the mycorrhizosphere (with roots and AMF in the same place). Different concentrations of PSF exudates were placed in either the hyphosphere or the mycorrhizosphere, and at the end of the experiment (8 weeks), the phosphatase activity of the AMF was measured. This research highlights that the enzymatic activity of AMF is modulated by PSF exudates, depending on whether these exudates are present in the hyphosphere or the mycorrhizosphere. Exudates in the hyphosphere, where PSF are directly associated with AMF hyphae, have a more pronounced effect on AMF extraradical alkaline phosphatases than acid phosphatases, and promote symbiosis efficiency. In contrast, PSF exudates in the mycorrhizosphere had a neutral or negative effect on symbiosis efficiency, improving the extraradical alkaline phosphatases of AMF and the acid phosphatases of the roots. Also, the effect depends on the fungal identity. AMF act as mediators in this context, improving communication between the roots and the hyphosphere microbiome. When exploring the soil, the hyphae encounter compounds produced by microorganisms, thus establishing a complex network of interactions. These interactions enhance the symbiotic efficiency of AMF, modulating the host plant without direct contact. These results show that microbial interactions not only influence the efficiency of phosphorus transfer to plants but also have broader implications for soil health and fertility management.

RevDate: 2025-11-18

Ye H, Šlipogor V, Hanson BT, et al (2025)

Associations between gut microbiota and personality traits: insights from a captive common marmoset (Callithrix jacchus) colony.

Microbiology spectrum [Epub ahead of print].

Recent studies have suggested associations between consistent inter-individual behavioral variation (i.e., animal personality) and gut microbiota. Non-human primates living under controlled conditions are valuable models to investigate diet-independent microbiome-host interactions. In this study, we investigated associations between specific gut microbiota members and personality traits, as well as group membership, sex, age class, breeding status, and relatedness of 26 captive common marmosets (Callithrix jacchus), maintained under the same diet and housing conditions. Personality was assessed using an established testing battery in repeated tests. Then, we collected a total of 225 fecal samples during the summers of 2017 and 2019 from five marmoset social groups for 16S rRNA gene amplicon sequencing. Within-individual microbiota variance was smaller than that between group members. Group members also exhibited more similar gut microbiota than individuals from different groups in each sampling year. Beta diversity of the gut microbiota was linked with personality traits, age class, sex, and breeding status, but not with genetic relatedness. We identified specific bacterial taxa associated with personality traits. In particular, members of the sulfite-reducing genus Desulfovibrio were enriched in more avoidant marmosets. Amplicon sequencing of the dissimilatory sulfite reductase gene dsrB confirmed this pattern, yet additionally revealed an unknown uncultured bacterium that was the predominant sulfite-reducing bacterium in the fecal samples and was linked to more explorative individuals. These findings highlight specific association patterns between identified microbial taxa and personality traits in captive common marmosets.IMPORTANCEThis study provides valuable insights into the intricate relationship between gut microbiota and host personality traits, using captive common marmosets as a model. By controlling for diet and housing conditions, it probes key host factors such as personality, age, sex, and social group membership, offering a robust framework for understanding microbiome-host interactions. The discovery of specific microbial taxa associated with personality traits, particularly the enrichment of sulfite-reducing genera in more avoidant individuals, underscores the potential of the gut microbiome to reflect or be associated with personality differences. These findings advance our understanding of microbiome-host dynamics and pave the way for future research on the mechanistic links between behavior and gut microbiota in other animal models and across broader ecological contexts.

RevDate: 2025-11-18

Ferreira J, Lievens B, H Rediers (2025)

Development of a spore-based confrontation assay to screen for biocontrol organisms with antagonistic activity against oomycete and fungal pathogens.

Journal of applied microbiology pii:8326519 [Epub ahead of print].

AIMS: Screenings for biocontrol organisms against fungal and oomycete pathogens are typically performed on mycelium. While this allows for high-throughput screenings, it omits a major actor in pathogenicity, i.e. the spores. This study aims to improve the screening strategy using a spore-based confrontation assay (SBCA), as well as comparing its performance to the traditional mycelium-based confrontation assay (MBCA) and microscopy analyses of spore germination.

METHODS AND RESULTS: The SBCA was used to screen for 38 candidate biocontrol bacteria against two relevant broad-spectrum phytopathogens, Botrytis cinerea and Phytophthora cactorum. The performance of the SBCA was benchmarked to the traditional mycelium-based confrontation assay and microscopy observations for spore germination inhibition. The SBCA demonstrated a higher hit rate and reproducibility than its counterparts. The bacteria tested exhibited diverse traits in vitro such as production of lytic enzymes, biosurfactant, bioactive volatile organic compounds, and cell-free extracts. These characteristics suggest potential biocontrol modes of action, such as antibiosis (via diffusible metabolites and enzymes) or competition for nutrients and space. For two Pseudomonas strains, the biocontrol activity against P. cactorum was confirmed in planta in a detached leaf assay.

CONCLUSIONS: This study showcases a versatile and robust spore-based screening that outperforms conventional screening methods. Through the use of the SBCA, two promising biocontrol strains with antagonistic activity against P. cactorum in strawberry were identified.

RevDate: 2025-11-18
CmpDate: 2025-11-18

Gao Y, Bai J, Zhou F, et al (2025)

ICCTax: a hierarchical taxonomic classifier for metagenomic sequences on a large language model.

Bioinformatics advances, 5(1):vbaf257.

MOTIVATION: Metagenomic data increasingly reflect the coexistence of species from Archaea, Bacteria, Eukaryotes, and Viruses in complex environments. Taxonomic classification across the four superkingdoms is essential for understanding microbial communities, exploring genomic evolutionary relationships, and identifying novel species. This task is inherently imbalanced, uneven, and hierarchical. Genomic sequences provide crucial information for taxonomy classification, but many existing methods relying on sequence similarity to reference genomes often leave sequences misclassified due to incomplete or absent reference databases. Large language models offer a novel approach to extract intrinsic characteristics from sequences.

RESULTS: We present ICCTax, a classifier integrating the large language model HyenaDNA with complementary-view-based hierarchical metric learning and hierarchical-level compactness loss to identify taxonomic genomic sequences. ICCTax accurately classifies sequences to 155 genera and 43 phyla across the four superkingdoms, including unseen taxa. Across three datasets built with different strategies, ICCTax outperforms baseline methods, particularly on Out-of-Distribution data. On Simulated Marine Metagenomic Communities datasets from three oceanic sites, DairyDB-16S rRNA, Tara Oceans, and wastewater metagenomic datasets, it demonstrates strong performance, showcasing real-world applicability. ICCTax can further support identification of novel species and functional genes across diverse environments, enhancing understanding of microbial ecology.

Code is available at https://github.com/Ying-Lab/ICCTax.

RevDate: 2025-11-17
CmpDate: 2025-11-18

Tinning Z, Kaestli M, Nowland SJ, et al (2025)

Dynamics of Bacterial and Vibrio Communities in Blacklip Rock Oysters in the Seasonal Tropics.

Microbial ecology, 88(1):125.

Cultivation of the tropical Blacklip Rock Oyster (BRO) (Saccostrea spathulata) is an emerging Indigenous-led aquaculture industry in the seasonal tropics of northern Australia. However, little is currently known about the potential for pathogen outbreaks in this species. We conducted a year-long study to establish a microbial baseline to identify potential oyster and human health risks to inform future food safety decision making in this nascent industry. In healthy oysters, we identified both the core microbiome of this oyster species and the presence of potential oyster and human pathogens. The core bacteriome comprised nine bacterial families, while the core vibriome comprised the animal pathogens Vibrio harveyi and V. owensii. The potential human pathogen V. parahaemolyticus was detected in some oysters during the wet season, during periods of increased rainfall, turbidity and total nitrogen. The bacteriome and vibriome of oysters were significantly different to the adjacent seawater and therefore we concluded that seawater is not an appropriate surrogate for pathogen risk surveillance in this developing industry. These results provide new knowledge on the microbiology of a previously understudied oyster species and will inform monitoring methods, harvesting and shellfish quality compliance in this emerging Indigenous-led industry.

RevDate: 2025-11-17
CmpDate: 2025-11-18

Zhou S, Bi J, Zhou S, et al (2025)

Community Assembly Mechanisms Underlying Divergent Responses of Indica and Japonica Rice Rhizosphere Microbiota to Drought Stress.

Microbial ecology, 88(1):126.

Drought stress markedly reduces rice yield, with notable genotypic variation in drought tolerance. While the rhizosphere microbiome is regarded as the second genome of plants, how the indica and japonica rice rhizosphere microbial communities respond to deficit irrigation and their relationship with yield remain to be elucidated. Here, we conducted field experiments using 12 indica and 12 japonica rice varieties under full and deficit irrigation regimes. Yield-related traits, including filled grain number, seed setting rate, two-plant yield, and thousand grain weight, were measured, and the rhizosphere microbial communities were characterized by 16S rRNA gene sequencing. In line with previous studies, japonica varieties showed superior drought resistance in terms of yield performance. Both rice genotype and irrigation regime significantly influenced the composition and functional potential of the rhizosphere microbiome. Compared to indica rice, the japonica rice rhizosphere was enriched with more beneficial microorganisms. Enrichment of nitrogen‑metabolism‑related groups, such as Microvirga and Nitrososphaeraceae, may contribute to rhizosphere nitrogen cycling and support nitrogen availability for the rice. Similarly, higher abundance of Streptomyces in japonica varieties under drought conditions may be associated with improved drought tolerance. These microbial genera were closely associated with rice yield. Moreover, the japonica rhizosphere microbiome was less disturbed by water limitation, showing higher stability. Overall, the rhizosphere microbiome of japonica rice exhibited functional optimization under drought stress by promoting the enrichment of beneficial and nitrogen-cycling microbes, thereby enhancing drought resistance and yield stability. This study demonstrated a significant correlation between rhizosphere microbial communities and rice yield, providing fundamental insights that may contribute to future strategies for optimizing crop productivity through microbiome management in sustainable agriculture.

RevDate: 2025-11-17

Zhou Y, Chang L, Sun H, et al (2025)

Evaluation of reclaimed treated wastewater on soil quality, microbial community and function in urban greening irrigation.

Journal of environmental management, 395:127958 pii:S0301-4797(25)03934-9 [Epub ahead of print].

Reclaimed treated wastewater (TWW) offers a sustainable irrigation alternative for urban greening amid freshwater scarcity. However, its impact on soil quality and microbial ecology in urban landscapes remains underexplored. This study assessed the effects of three TWW types and one TWW-purified water mixture on soil properties, heavy metal accumulation, enzyme activity and microbial community dynamics in Common Nandina (Nandina domestica Thunb.) systems over three- and five-month in Nanjing, China, using a metagenomic approach. The results showed that TWW irrigation significantly increased soil nitrogen, phosphorus content and pH (P < 0.05), with stronger effects observed at three-month (P < 0.05). Soil heavy metal content varied, with Cr and As exhibiting potential accumulation. Enzyme activity (N-acetyl-glucosaminidase and phosphatase) was positively influenced by TWW irrigation at three-month. Metagenomic analysis revealed significant shifts in microbial community composition, particularly fungi, with Mucoromycota increasing and Ascomycota decreasing under TWW. The Normalized Stochasticity Ratio indicated increased stochasticity in microbial assembly under TWW irrigation (P < 0.05). Functionally, TWW increased abundance of functional genes related to amino acid metabolism and peroxisomes (P < 0.05), but decreased degradation genes for aromatic compounds. TWW also increased the abundance of antibiotic resistance genes (ARGs), particularly those related to triclosan and glycopeptide, and plant pathogenic genera like Aspergillus and Fusarium. The findings suggest that while TWW irrigation improves certain soil properties and microbial functions in the short term, it may pose ecological risks from heavy metal and microbial contamination, offering key insights for sustainable urban irrigation strategies.

RevDate: 2025-11-17
CmpDate: 2025-11-17

Wei D, Hu S, Tang T, et al (2025)

Confinement Reduces Surface Accumulation of Swimming Bacteria.

Physical review letters, 135(18):188401.

Many swimming bacteria naturally inhabit confined environments, yet how confinement influences their swimming behaviors remains unclear. Here, we combine experiments, continuum modeling, and particle-based simulations to investigate near-surface bacterial swimming in dilute suspensions under varying confinement. Confinement reduces near-surface accumulation and facilitates bacterial escape. These effects are quantitatively captured by models incorporating the force quadrupole, a higher-order hydrodynamic singularity, that generates a rotational flow reorienting bacteria away from surfaces. Under strong confinement, bacterial trajectories straighten due to the balancing torques exerted by opposing surfaces. These findings highlight the role of hydrodynamic quadrupole interactions in near-surface bacterial motility, with implications for microbial ecology, infection control, and industrial applications.

RevDate: 2025-11-17

Wenten IG (2025)

Rethinking Biofilm Engineering and Fouling Resistance in Membrane Bioreactors.

Langmuir : the ACS journal of surfaces and colloids [Epub ahead of print].

Membrane bioreactors (MBRs) are increasingly recognized as a key technology in sustainable wastewater treatment, offering a high effluent quality through the integration of biological degradation and membrane filtration. Among the critical factors influencing their performance are biofilm dynamics and membrane fouling. This article critically examines recent advances in biofilm engineering and antifouling strategies for MBRs, with an emphasis on microbial community modulation, quorum quenching, and hydrodynamic control to improve biofilm stability. In parallel, the review examines material-based and biological methods to mitigate membrane fouling, emphasizing multifunctional surfaces and emerging biocontrol strategies. Key operational challenges, such as energy consumption, cleaning frequency, and membrane aging, are evaluated alongside future research directions in materials design, microbial ecology, and real-time system optimization. The integration of these innovations is essential for advancing MBR technologies that are robust, resource-efficient, and aligned with circular economy principles.

RevDate: 2025-11-17

Weagley JS, Cárdenas LAC, Romani A, et al (2025)

Differential Microbial Community Assembly Following Co-housing versus Microbiota Transplant.

The ISME journal pii:8325228 [Epub ahead of print].

Mouse models are vital tools for discerning the relative contributions of host and microbial genetics to disease, often requiring the transfer of microbiota between different mouse strains. Transfer methods include antibiotic treatment of recipients and colonization using either co-housing with donors or the transplantation of faecal or caecal donor material. However, the efficiency and dynamics of these methods in reconstituting recipients with donor microbes is not well understood. We thus directly compared co-housing, faecal transplantation, and caecal transplantation methods. Donor mice from Taconic Biosciences, possessing distinct microbial communities, served as the microbial source for recipient mice from Jackson Laboratories, which were treated with antibiotics to disrupt their native microbiota. We monitored bacterial and viral populations longitudinally over the course of antibiotics treatment and reconstitution using 16S rRNA gene sequencing, quantitative PCR, and shotgun sequencing of viral-like particles. As expected, antibiotic treatment rapidly depleted microbial biomass and diversity, with slow and incomplete natural recovery of the microbiota in non-transfer-recipient control mice. Although all transfer methods reconstituted recipient mice with donor microbiota, co-housing achieved this more rapidly for both bacterial and viral communities. Overall, faecal and caecal transplant resulted in highly similar colonization processes with some minor variation in enrichment for two specific bacterial families. This study provides valuable insights into microbial ecology, as well as the dynamics underlying experimental microbial transfer methods, enhancing reproducibility and informing best practices for microbiota transfer in mouse models.

RevDate: 2025-11-17

Van Beek JM, Robles G, Mewalal R, et al (2025)

A collection of archaeal 16S rRNA Clone-FISH cultures for probe validation in fluorescence in situ hybridization experiments.

Microbiology resource announcements [Epub ahead of print].

We present a collection of 30 Escherichia coli cultures (Clone-FISH cultures), each carrying a plasmid for the heterologous expression of a (near) full-length 16S rRNA gene from 1 of 30 lineages of archaea, including 17 yet uncultured ones. We make these clones available for use as controls in fluorescence in situ hybridization experiments.

RevDate: 2025-11-17

Xiong M, Kuang W, Liu Z, et al (2025)

Quercetin alleviates ulcerative colitis via regulating gut microbiota and tryptophan metabolism.

mSystems [Epub ahead of print].

UNLABELLED: Quercetin, a natural flavonoid in traditional Chinese medicinal plants, has shown promise in alleviating ulcerative colitis symptoms despite uncertainties about its exact mode of action. This study explored how quercetin influences tryptophan breakdown and gut bacterial populations in mice with chemically induced colitis. The treatment demonstrated measurable improvements-normalizing body weight, reducing spleen enlargement, lowering clinical severity scores, preserving colon structure, and healing tissue damage. Through advanced microbiome profiling and metabolic analysis, researchers observed increased populations of helpful gut microbes alongside higher concentrations of tryptophan byproducts. These biochemical shifts stimulated the aryl hydrocarbon receptor system, which plays a key role in restoring gut lining integrity. The collective evidence points to quercetin's therapeutic potential through its dual action on microbial ecology and tryptophan-derived signaling pathways.

IMPORTANCE: Ulcerative colitis is a chronic inflammatory disease with limited effective therapeutic options. In this study, quercetin-a flavonoid commonly found in traditional Chinese medicinal herbs-was shown to relieve colitis symptoms by reshaping gut microbiota and restoring tryptophan metabolism. Notably, the increase in indolelactic acid, a key microbial metabolite, led to activation of the aryl hydrocarbon receptor, which supports intestinal barrier integrity and dampens inflammation. These findings reveal a gut microbiota-derived metabolite-host signaling axis as a central mechanism of action, highlighting the potential of quercetin as a microbiota-targeted therapeutic approach for UC.

RevDate: 2025-11-17
CmpDate: 2025-11-17

Dey P (2025)

Genes, guts, and microbes: decoding host-driven microbial regulation using intestine-specific conditional knockouts.

Frontiers in immunology, 16:1674913.

This narrative review underscores the influence of host genetics in actively regulating gut microbiota composition and function, highlighting the distinctive advantages of intestine-specific conditional knockout (cKO) models in gut microbiome research. In contrast to whole-body knockouts or germ-free animals, these precision models, enabled by Cre-loxP technology, eliminate confounding systemic effects to elucidate how localized host genes within intestinal cells regulate the gut microbial ecology. The review identifies three fundamental host-driven regulatory mechanisms through the analysis of specific gene deletions: (1) barrier integrity (e.g., mucus and junction proteins), (2) immune defenses (e.g., antimicrobial peptides and glycan synthesis), and (3) metabolic signaling (e.g., bile acid receptors and glucose transporter). These pathways jointly impose microbial symbiosis, and their disruption leads to dysbiosis characterized by increased abundance of pathobionts (e.g., Escherichia, Proteobacteria), directly connecting host genetics to inflammatory and metabolic disorders. This host-centric viewpoint emphasizes the gut as an active regulator, rather than a passive microenvironment for the microbiota, providing significant insights for creating tailored therapeutics that focus on host pathways to restore microbial balance in disorders such as inflammatory bowel diseases.

RevDate: 2025-11-17
CmpDate: 2025-11-17

Phoo MTP, Dechathai T, Singkhamanan K, et al (2025)

Pseudomonas aeruginosa affects Acinetobacter baumannii's growth, gene expression and antibiotic resistance in in vitro co-culture system.

Current research in microbial sciences, 9:100499 pii:S2666-5174(25)00160-9.

Pseudomonas aeruginosa and Acinetobacter baumannii are opportunistic pathogens co-isolated frequently in the same infection sites. In this study, we aimed to elucidate the interaction between P. aeruginosa and A. baumannii in in vitro co-culture system. Growth analysis showed that P. aeruginosa PA01 unilaterally exerts a negative effect on the growth of A. baumannii SK005. A. baumannii alone exhibited an altered transcriptome pattern, especially in the genes for metabolic pathways. Strong upregulation of genes in iron acquisition systems (acinetobactin, baumannoferrin, 2,3-dihydroxybenzoic acid synthesis cluster, and Feo iron transport system) and downregulation of iron-storage genes (bacterioferritin) were the most prominent changes. In terms of antibiotic resistance, we observed the downregulation of the fosfomycin resistance gene fosB. Strikingly, the phenotypic analysis demonstrated that A. baumannii in co-culture is more vulnerable to fosfomycin than in monoculture conditions, while it is more resistant to cefoxitin and imipenem. This study broadens our understanding of microbial ecology in co-infection settings by highlighting the fact that mixed pathogens do not always undergo interaction to a mutually equivalent extent.

RevDate: 2025-11-17
CmpDate: 2025-11-17

Zhang Z, Jia L, Liu B, et al (2025)

Maternal gut microbiota and placenta-derived tissues microbes are important for initial gut microbial colonization in infants.

Frontiers in microbiology, 16:1631590.

BACKGROUND: Early infant gut microbiota colonization, influenced by various factors, significantly affects future growth and development. However, results related to how the initial microbial ecology is established in the infant gut remain inconsistent.

RESULTS: In this study, we collected maternal and infant feces, vaginal secretions, placental tissues, breast milk, amniotic membrane tissues, umbilical cord blood, and breast skin for homology comparisons and for exploring the main sources of infant intestinal microbiota. Our results revealed that early infant gut microbiota originated mainly from the vertical transmission of maternal microbiota, and that vaginal microbiota did not affect infant gut microbiota colonization. Microbiota was detected in the placenta, supporting the idea that the uterus is not sterile. Moreover, we verified microbial composition-related similarities in the amniotic tissues and umbilical cord blood, further validating our hypothesis that gut microbiota in the early stages of infancy are mainly vertically transmitted from the mother and placenta-derived tissues also play a significant role in the formation of the infant's initial gut microbiota. Notably, none of the hereby-mentioned influences (i.e., gender, delivery mode, feeding mode, and Hepatitis B virus) affected significantly infant gut microbiota colonization.

CONCLUSION: This study demonstrated that infant intestinal microbiota resulted from microbiotic co-provision from multiple maternal sites. In addition to the maternal gut microbiota, the placenta-derived tissues is the relevant contributor to initial infant gut microbiota, providing strong evidence for the source colonization of the infant gut microbiota.

RevDate: 2025-11-17
CmpDate: 2025-11-17

Addo SO, Addo M, DeWitt ME, et al (2025)

Knowledge, Attitude and Practices of Abattoir Workers in Kumasi Towards Ticks and Tick-Borne Pathogens.

Public health challenges, 4(4):e70167 pii:PUH270167.

The high dependence on livestock in Ghana comes with the risk of zoonotic tick-borne pathogen infection. Abattoir workers are especially at risk due to their frequent contact with livestock that are infested with ticks and tick-borne pathogens. This study sought to assess the knowledge, attitude and practices of abattoir workers in Kumasi towards ticks and tick-borne pathogens. A total of 130 workers were recruited from the Kumasi abattoir (92), Suame abattoir (24) and Akwatia Line slaughter slab (14). The respondents were males, mostly aged between 46 and 55 years (36.2%), had no form of education (43.8%) and had >10 years (68.5%) of working experience. Given that a significant number of the workers handled live animals (95.4%) or dead animals or animal parts (87.7%), were involved in slaughtering (69.2%) and had experienced tick bites (81.5%), there was a risk of tick-borne pathogen infection. However, only 35.4% thought humans can get diseases from tick bites, and 58.5% of the respondents believed tick bites lead to the development of a tick-borne disease. It was observed that education (p = 0.008) had a significant influence on the risk of zoonotic tick-borne pathogen infection, with 52% of the respondents with no education believing humans cannot get infections from ticks. The findings of this study indicate that the abattoir workers are at risk of zoonotic tick-borne infections, and there is a need for frequent education as well as the adoption of effective tick control and preventive measures.

RevDate: 2025-11-16

Andonotopo W, Bachnas MA, Dewantiningrum J, et al (2025)

The fetal exposome and Preterm Birth: a systematic synthesis of environmental exposures and multi-omics evidence.

Journal of perinatal medicine [Epub ahead of print].

OBJECTIVES: Preterm birth (PTB), defined as delivery before 37 weeks of gestation, is a leading cause of neonatal mortality and long-term developmental impairment. Its complex etiology, spanning environmental, genetic, psychosocial, and socio-economic domains, limits effective prediction and prevention. We systematically synthesized evidence on how environmental exposures influence PTB risk through multi-omic disruptions within a fetal exposome framework.

METHODS: A comprehensive literature search was conducted in major biomedical databases, following PRISMA guidelines. Ninety-five human studies published through May 2025 were included, encompassing exposures such as ambient air pollution, endocrine-disrupting chemicals, maternal stress, nutrition, occupational hazards, climate variability, and microbiome alterations. Two reviewers independently extracted data (exposure type, omics platform, biospecimen, PTB subtype) with inter-rater reliability assessment, and study quality was evaluated using the Newcastle-Ottawa Scale. Findings were narratively stratified by exposure category, study design, and spontaneous vs. indicated PTB.

RESULTS: Environmental exposures were consistently associated with disruptions in oxidative stress, inflammation, immune regulation, hormonal signaling, placental aging, and microbial ecology, mediated by multi-omic signatures in maternal, placental, and fetal tissues. Candidate biomarkers show promise for early risk stratification but lack validation and population-level predictive performance due to heterogeneous exposure assessment and study design.

CONCLUSIONS: Integrating fetal exposome concepts with multi-omics enhances mechanistic insight into PTB risk and may support biomarker discovery and precision-guided prenatal interventions. Clinical translation requires standardized exposure measurement, biomarker validation, and equity-focused implementation.

RevDate: 2025-11-16

Gloria LD, Lotti T, van Loosdrecht MC, et al (2025)

Who calls granules "home"? Domain-spanning meta-analysis charting microbial ecosystems underlying aerobic granular sludge reactors.

Bioresource technology pii:S0960-8524(25)01624-4 [Epub ahead of print].

The theatre of activity of complex microbial communities underpins the Aerobic Granular Sludge (AGS) systems, resulting in efficient wastewater treatment. Here, we present the first meta-analysis of DNA sequencing data from both published and newly generated AGS samples, aiming to define the "core microbiota" of AGS reactors, consisting of bacteria, archaea, eukaryotes and DNA viruses consistently featured and shared across different scales and operational settings. Briefly, the results indicated that a sequencing depth of at least 10 GB is required to profile the majority of the AGS community, revealed the core taxa, detected the recurrent presence of the uncultured genus ADurb.Bin028 in full-scale reactors and identified Rotaria and Diploscapter, as well as the sessile ciliates Stentor and Thuricola, as the most abundant eukaryotes in AGS. In conclusion, this work provided a taxonomic overview of AGS' common microbes and addressed potential technical caveats, aiming to establish a reference for future studies.

RevDate: 2025-11-15
CmpDate: 2025-11-15

Berkhout MD, de Ram C, Boeren S, et al (2025)

Probiotic Engraftment of Akkermansia muciniphila in an In Vitro Synthetic Microbial Community.

Microbial ecology, 88(1):123.

Akkermansia muciniphila is a specialist mucin glycan-degrader that is common in the human gut. A. muciniphila is associated with host health and therefore proposed as a next-generation probiotic. However, it is unknown if consumption of live and active A. muciniphila will be effective in terms of survival and engraftment in the gut microbiome. Furthermore, it is of interest whether introduction of A. muciniphila would influence the resident mucosal microbiota. To this end, we investigate the addition of live A. muciniphila to a stable in vitro microbial mucin glycan-degrading synthetic community. A. muciniphila engrafted in this synthetic community and actively degraded mucin using essential mucin glycan-degrading enzymes. Addition of A. muciniphila did not induce major compositional changes, except that Bacteroides thetaiotaomicron increased in relative abundance at the expense of Bacteroides caccae. At the metaproteomic level, community function was not significantly affected, as peptidase, fucosidase, galactosidase and sulfatase expression remained stable. However, sialidase was significantly enriched after A. muciniphila addition, which can be explained by the relative increase of generalist glycan-degrader B. thetaiotaomicron. Overall, we show that a community without A. muciniphila still harbours a niche for this bacterium, but that A. muciniphila did not induce major changes in the in vitro mucosal synthetic community. This suggests that A. muciniphila applied as a probiotic can engraft and exert its beneficial effects on the host, without major impact on the human gut mucosal microbiota composition and function and warrants further research into A. muciniphila engraftment in vivo.

RevDate: 2025-11-15
CmpDate: 2025-11-15

Cambronero-Heinrichs JC, Pepori AL, Pecori F, et al (2025)

Microbial Interactions Support the Role of Ambrosia Beetles as Potential Vectors of Dutch Elm Disease.

Microbial ecology, 88(1):124.

Dutch elm disease (DED) has caused devastating pandemics in natural elm populations across Europe, North America, and Asia. The primary vectors of DED are native elm-associated bark beetles of the genus Scolytus. However, there is evidence suggesting that ambrosia beetles may also carry Ophiostoma novo-ulmi and potentially transmit it to elm trees. In this study, we explored microbial interactions and host selection mechanisms that could support the role of ambrosia beetles as vectors of O. novo-ulmi. Our study showed that females of Anisandrus dispar, Xyleborinus saxesenii, Xylosandrus crassiusculus, and Xylosandrus germanus emerging from both DED-infected and healthy elm logs carried O. novo-ulmi DNA. Furthermore, we showed that none of the tested ambrosia beetle fungal symbionts was adversely affected by O. novo-ulmi, while Dryadomyces spp. and the bacterial symbiont Erwinia sp. 1C4 partially restricted or inhibited O. novo-ulmi growth without fully suppressing it. Overall, these findings provide additional evidence supporting the potential role of ambrosia beetles as vectors of DED and emphasize the need for further research on this understudied insect-pathogen relationship.

RevDate: 2025-11-14

Casanova-Hernández D, Pinacho-Pinacho CD, Calixto-Rojas M, et al (2025)

Challenging the paradigm: the Asian fish tapeworm (Schyzocotyle acheilognathi, Yamaguti 1934) lacks an intrinsic symbiotic bacterial community.

International microbiology : the official journal of the Spanish Society for Microbiology [Epub ahead of print].

Schyzocotyle acheilognathi is an invasive generalist cestode with a high capacity for adaptation to multiple hosts and freshwater environments. Recent reports suggest that this parasite possesses an intrinsic symbiotic microbiota distinct from that of its fish hosts, and its presence induces gut dysbiosis in the host. In this study, we reassessed these ideas. For this, we collected naturally parasitized fish specimens from different locations in Mexico, encompassing different host species, including Cyprinus carpio, Pseudoxiphophorus bimaculatus, Tlaloc hildebrandi, and Vieja hartwegi. We also tested whether this parasite induces a dysbiotic process in the gut bacterial community of Tlaloc hildebrandi. Parasites were identified based on morphological and molecular criteria, and their bacterial communities were characterized using metataxonomy. Our results revealed that S. acheilognathi does not harbor a consistent microbial community among the different host species surveyed. We also did not detect any dysbiotic effect on the gut microbiota of Tlaloc hildebrandi. These findings contradict previous data and provide evidence of the loose relationship between this parasite and bacteria, which we propose could be a part of its successful generalist strategy. The results presented herein offer a novel perspective on the quest for understanding the microbial ecology in generalist cestodes of freshwater fish.

RevDate: 2025-11-14
CmpDate: 2025-11-15

Cao D, Huang W, Pang M, et al (2025)

Investigation of the Alterations in the Gut Microbiota and Intestinal Mucosa in Mice Infected with Echinococcus multilocularis.

Acta parasitologica, 70(6):211.

PURPOSE: Alveolar echinococcosis (AE), a zoonotic parasitic disease caused by the larval metacestode of Echinococcus multilocularis (E. multilocularis), primarily affects the liver and can invide other organs. Given its extremely poor prognsis, witha 10-year mortality rate exceeding 90% in untreated cases, this study aimed to investigate the characteristics and compositional alterations of the intestinal microbiota in AE-infected hosts and evaluate associated intestinal mucosal damage.

METHODS: We established a mouse model of AE for analysis. Fecal samples were collected from 12 AE-infected mice and 12 age-matched healthy controls at 3 and 6 months post-infection. Gut microbiota composition was assessed by 16S rRNA gene sequencing. Intestinal tissues were subjected to histopathological exnamination using hematoxylin-eosin staining (H&E staining), Alcian blue-glucogen staining (AB-PAS staining), and Lendrum's fluorescent peach red staining, to evaluate mucosal structural integrity and quantify the Paneth and goblet cells.

RESULTS: The analysis revealed significant alterations in intestinal microbiota diversity and composition in AE-infected mice compared with controls, with changes becoming more pronounced as the infection progressed. Minimal disruption in microbial ecology was observed at 3 months, whereas substantial reductions in alpha diversity and distinct shifts in beta diversity emerged after 6 months of chronic infection. Phylum-level analysis showed an early increase in Verrucomicrobiota, Bacteroidota, and Campylobacterota at 3 months, followed by a marked enrichment of Verrucomicrobiota and Actinobacteriota at 6 months when compared with controls. At the genus level, AE infection led to a rapid depletion of Ligilactobacillus and Lactobacillus between 3 and 6 months, while Akkermansia abundance significantly increased. Histopathological examination of intestinal tissue further demonstrated severe mucosal damage, including villous atrophy, reduced crypt depth, a pronounced decrease in Paneth cell density (P < 0.01), and reduced goblet cell counts (P < 0.05), collectively indicating compromised intestinal barrier integrity.

CONCLUSION: AE infection induces progressive gut microbiota dysbiosis and compromises intestinal barrier integrity. The specific microbial shifts, particularly the depletion of Ligilactobacillus and enrichment of Akkermansia, represent promising diagnostic biomarkers and potential targets for probiotic supplementation or microbial modulation. To further clarify their roles, future research should incorporate multi-omics strategies, including metagenomics and metabolomics, within larger cohorts to better characterize microbiota-host metabolic interactions and to validate stage-specific microbial biomarkers in AE.

RevDate: 2025-11-14

Devarajan B, Sharma S, Mills B, et al (2025)

Dysbiosis of Bacterial and Fungal Microbiomes Affects the Disease Process and Treatment Outcome in Fungal Keratitis.

Experimental eye research pii:S0014-4835(25)00518-4 [Epub ahead of print].

Fungal keratitis (FK) is a severe eye infection mainly caused by Aspergillus flavus and Fusarium solani. We examined the changes in bacterial and fungal microbiome profiles over a week of disease progression, treatment, and clinical status using targeted next-generation sequencing (NGS). Samples were collected from infected and healthy contralateral eyes of 25 FK patients and one eye of 10 healthy, non-infected cataract controls. QIIME (Quantitative Insights into Microbial Ecology) and MicrobiomeAnalyst were utilised for the data analysis. There was a reduction in beneficial bacteria like Prevotella, Lactobacillus, and Leuconostoc in FK patients compared to the control samples. On the other hand, opportunistic bacteria including Clostridium, Bifidobacterium, and Pseudomonas increased in FK patients. Aspergillus, Colletotrichum, and Basidiobolus were more abundant in keratitis patients, whereas Malassezia and Trichoderma were less abundant. This dysbiosis was also evident in the uninfected contralateral eyes of FK patients. Treatment resulted in significant changes in bacterial genera like Dolosigranulum, Sutterella, and Akkermansia, and fungal genera such as Myrothecium, Corynespora, and Penicillium. Further, treatment returned them to the control group levels, except for Akkermansia and Corynespora. Among the treated patients, a large subset remains nonresponsive to treatment. This treatment outcome, responder versus non-responder, was reflected in the abundance of bacterial genera such as Tannerella, Sutterella, Odoribacter, and fungal genera such as Coprinellus and Volutella. This study highlights the clinical relevance of microbiome signatures in FK, demonstrating bilateral dysbiosis, integrated bacterial-fungal profiling, and correlations with treatment outcomes. These findings suggest potential for microbiome-informed diagnostics, prognostic biomarkers, and risk stratification.

RevDate: 2025-11-14
CmpDate: 2025-11-14

Markfeld M, Titcomb G, Randriamoria TM, et al (2025)

Differential Assembly of Core and Non-Core Host-Microbe Network Structures Along a Land-Use Change Gradient.

Ecology letters, 28(11):e70255.

Microbial communities are fundamental to host health, yet their assembly dynamics under environmental change remain poorly understood. We analysed individual-level host-microbe networks in the non-native wild black rats (Rattus rattus) across a land-use gradient in Madagascar. By applying a moving prevalence threshold, we distinguished between core and non-core microbes and compared the assembly drivers shaping their network structures. Non-core microbes formed fragmented, modular networks shaped mainly by heterogeneous selection, reflecting environmental filtering. In contrast, core microbes exhibited stable, less modular networks driven primarily by stochastic ecological drift. These distinct assembly processes persisted across thresholds, highlighting fundamental differences in microbial structuring. Land-use change significantly influenced the modular structure of non-core microbes but had minimal effects on core microbes, demonstrating the differential sensitivity of microbial groups to environmental variation. This study advances our understanding of host-microbe interactions and provides a framework for assessing microbiome assembly under anthropogenic change.

RevDate: 2025-11-14

Maillard F, Klinghammer F, Beatty BH, et al (2025)

Keystone protist suppression triggers mesopredator release and biotic homogenization in complex soil microbial communities.

The ISME journal pii:8323206 [Epub ahead of print].

The keystone species concept holds that certain members of an ecological community, despite their low abundance, exert disproportionately large effects on species diversity and composition. In microbial ecology, experimental validation of this concept has been limited because targeted removal of individual species remains technically challenging. Here, we developed a procedure to test the keystone species concept within a soil microbial food web by selectively suppressing a protist predator at the microscale via UV-induced phototoxicity in a microfluidic soil chip system. We targeted a hypotrich ciliate (subclass Hypotrichia), and combined microscopy with high-throughput amplicon sequencing of microbial taxonomic markers to assess, across multiple trophic levels, how its suppression affected microbial community abundance, diversity, and composition. Over the 20-day incubation, the chip system supported complex communities of bacteria, fungi, and protists. Following Hypotrichia suppression, two distinct ecological responses were observed: first, an increase in the relative abundance of flagellates, consistent with mesopredator release, accompanied by a significant rise in overall protist diversity; second, a convergence in protist community composition, indicative of biotic homogenization. Bacterial community abundance, richness, and composition remained unchanged, likely due to compensatory predation from a relative increase in bacterivorous flagellates. In contrast, fungal diversity decreased, presumably because the altered protist community favored facultative fungal consumers. Collectively, these findings provide direct experimental evidence that low abundance microbial predators can function as keystone species, modulating predator community composition and diversity, and exerting cascading effects on lower trophic levels within microbial brown food webs.

RevDate: 2025-11-14
CmpDate: 2025-11-14

Wang IC, Swanson JL, Waters JL, et al (2025)

Alteration of gut microbial ecology by the direct activation of the brain: Inverse gut-microbiome-brain dynamics.

iScience, 28(11):113709.

The gut-microbiome-brain axis is a bidirectional communication system influencing host physiology and overall fitness. While "bottom-up" effects-where gut microbes influence brain function and behavior-are well established, direct evidence for "top-down" modulation-where the brain shapes the gut microbial ecology-remains elusive. Here, we show that the selective expression of the bacterial ion channel mNaChBac in glutamatergic lateral habenula (LHb) neurons increases their bursting activity and leads to endophentypes associated with depression. Importantly, this chronic activation leads to changes in the gut microbiome composition over time, as reflected by shifts in alpha-diversity and alterations in specific microbial taxa. These findings provide direct evidence that the persistent activation of the brain acts as a selective pressure that affects the stability and diversity of the gut microbiome, providing a new dimension by which gut-microbiome-brain interactions may cooperate to modulate host physiology and health.

RevDate: 2025-11-13
CmpDate: 2025-11-14

Zhang P, Roque B, Romero P, et al (2025)

Red seaweed supplementation suppresses methanogenesis in the rumen, revealing potentially advantageous traits among hydrogenotrophic bacteria.

Microbiome, 13(1):231.

BACKGROUND: Macroalgae belonging to the genus Asparagopsis have shown to reduce methane (CH4) production during rumen fermentation, while increasing feed efficiency when added to the feed of cattle. However, little is known about how the rumen microbiome responds to Asparagopsis supplementation, and how changes in the microbiome may contribute to changes in rumen function and host phenotype. Here, we generated and analyzed metagenomic and metatranscriptomic data from the rumen microbiome from cows receiving (treatment) and not receiving (control) an Asparagopsis armata supplemented diet.

RESULTS: Using a combination of metatranscriptome and metagenome analysis, we found that reduction of CH4 emission from animals receiving A. armata was coupled to a significant reduction in the transcription of methanogenesis pathways. Additionally, a significant decrease in the transcription of genes for carbon catabolism and a reorganization of carbon catabolic gene expression occurred at the species level within the rumen microbiome of animals that received red seaweed with their diet. Increased H2 production, a consequence of methanogenesis suppression, was coupled to a significant increase in the transcription of hydrogenases that mediate hydrogenotrophic metabolism in the treatment group. Metatranscriptome analysis identified a single metagenome assembled genome (MAG) of a Duodenibacillus sp., a hitherto uncultured hydrogenotrophic bacterial species, as the dominant driver of this transcriptional change.

CONCLUSIONS: Comparative genomic analysis between the Duodenibacillus sp. and other hydrogenotrophic rumen organisms revealed metabolic traits that may provide Duodenibacillus sp. with a competitive advantage in H2 scavenging. Our findings provide an initial understanding of how the rumen microbiome responds to a promising CH4 reducing feed additive and serve as a model for alternative stable rumen microbiome states that produce less methane and increase animal productivity. Ultimately, insights from the work presented here might enable the development of advanced microbiome-based strategies to reduce enteric methane production.

RevDate: 2025-11-13
CmpDate: 2025-11-14

Modolon F, N Garritano A, J Hill L, et al (2025)

Putative promiscuous symbionts in deep-sea corals and crinoids may contribute to nitrogen cycling.

Microbiome, 13(1):234.

BACKGROUND: Crinoids (feather stars) are frequently found in association with corals, yet the physiological and microbial interactions between these organisms remain poorly understood. Both corals and crinoids host symbiotic microorganisms, but the functional roles of these symbionts, particularly in deep-sea environments, are largely unexplored. This study characterizes the microbiomes of the deep-sea corals Desmophyllum pertusum and Solenosmilia variabilis and their associated crinoid Koehlermetra sp. (Thalassometridae) from the Campos Basin, Brazil, to investigate potential cross-host microbial interactions and their ecological implications. We used multiple approaches for this investigation, including amplicon sequencing surveys, genome-resolved metagenomics, and fluorescence in situ hybridization.

RESULTS: We found that the same endosymbiotic members of the families Endozoicomonadaceae and Nitrosopumilaceae inhabit both corals and the crinoids, suggesting promiscuity in host-symbiont relationships. Metagenomic analysis revealed a novel and dominant Endozoicomonas species (E. promiscua sp. nov.), whose genome encodes pathways for dissimilatory nitrate reduction to ammonia (DNRA). This metabolic capability could provide a substrate for ammonia-oxidizing archaea (Nitrosopumilaceae), indicating a potential cross-host nitrogen-cycling network. Shared microbial taxa between corals and crinoids further support the hypothesis of symbiont promiscuity, where metabolic redundancy may facilitate colonization across species.

CONCLUSIONS: Our findings suggest that nitrogen cycling plays a key role in structuring microbial symbioses in deep-sea coral-crinoid holobionts. The promiscuous distribution of symbionts across hosts implies that metabolic interactions, such as DNRA-driven ammonia provisioning, could underpin resilience in nutrient-limited environments. This study highlights the importance of microbial versatility in deep-sea ecosystems and provides new insights into how cross-host symbiosis may contribute to biogeochemical cycling in the ocean. Video Abstract.

RevDate: 2025-11-13

Sieders M, Candry P, S El Aidy (2025)

Hydrogel-based experimental models of the gastrointestinal tract.

Microbiome, 13(1):233.

The gut microbiome plays a pivotal role in human health, yet its complexity has long eluded detailed study under physiologically relevant conditions. Hydrogel-based models are revolutionizing microbiome research by bridging the gap between traditional in vitro systems and the complexity of in vivo environments. These advanced systems replicate key physical and biochemical features of the gastrointestinal tract, offering unprecedented opportunities to study microbial behavior, adaptation, and interactions within three-dimensional, tunable architectures. Unlike suspension cultures, hydrogels provide porous, mucosa-like environments that enable the cultivation of mucosa-associated microbes, co-culturing with human cells, and mimicking healthy and disease-related states. This review explores the transformative potential of hydrogel matrices in unveiling the spatial organization, nutrient gradients, and community communication that define microbial ecosystems. By integrating the benefits of in vitro and in vivo models, hydrogel-based platforms promise to accelerate discoveries in microbiome science, with far-reaching implications for understanding human health and developing targeted therapeutics. Video Abstract.

RevDate: 2025-11-13
CmpDate: 2025-11-13

Baral T, Maile A, Adimurthy NH, et al (2025)

Exploring gut microbiota and its predicted functions in pulmonary tuberculosis: A multi-regional study using public 16S datasets.

PloS one, 20(11):e0336337 pii:PONE-D-25-41202.

BACKGROUND: Pulmonary tuberculosis, caused by the bacillus Mycobacterium tuberculosis, remains a major global health challenge, particularly in developing countries. In this study, we analyzed publicly available 16S amplicon sequencing datasets from four geographical locations using a single workflow.

METHODS: We employed Quantitative Insights Into Microbial Ecology v.2 for microbial diversity analysis and Phylogenetic Investigation of Communities by Reconstruction of Unobserved States v.2 for functional pathway predictions of the gut microbiota in patients with PTB and antitubercular therapy.

RESULTS: Our analysis revealed statistically significant alpha diversity differences in West Africa with decreased microbial diversity in pulmonary tuberculosis patients after two months of antitubercular therapy. Additionally, there were no statistically significant differences observed in pairwise comparisons within the same location or in the aggregate beta diversity of the datasets. The predicted microbial metabolic pathways related to vitamin biosynthesis, amino acid synthesis, and energy production were depleted in pulmonary tuberculosis patients following antitubercular therapy.

CONCLUSIONS: The observed alterations of gut microbial diversity and predicted functional profile underscores the influence of antitubercular therapy on gut health, suggesting that longer treatment durations may aggravate these alterations in gut microbial function. Moreover, geographical location exerts a more significant impact on microbial diversity than the disease state in a specific location, highlighting the potential for precision medicine to tailor interventions based on individual or regional microbiome characteristics.

RevDate: 2025-11-13
CmpDate: 2025-11-13

Mukherjee A, Tan BH, S Swarup (2025)

In Silico Prediction and In Vitro Validation of Bacterial Interactions in the Plant Rhizosphere Using a Synthetic Bacterial Community.

Bio-protocol, 15(21):e5496.

The rhizosphere, a 2-10 mm region surrounding the root surface, is colonized by numerous microorganisms, known as the rhizosphere microbiome. These microorganisms interact with each other, leading to emergent properties that affect plant fitness. Mapping these interactions is crucial to understanding microbial ecology in the rhizosphere and predicting and manipulating plant health. However, current methods do not capture the chemistry of the rhizosphere environment, and common plant-microbe interaction study setups do not map bacterial interactions in this niche. Additionally, studying bacterial interactions may require the creation of transgenic bacterial lines with markers for antibiotic resistance/fluorescent probes and even isotope labeling. Here, we describe a protocol for both in silico prediction and in vitro validation of bacterial interactions that closely recapitulate the major chemical constituents of the rhizosphere environment using a widely used Murashige & Skoog (MS)-based gnotobiotic plant growth system. We use the auto-fluorescent Pseudomonas, abundantly found in the rhizosphere, to estimate their interactions with other strains, thereby avoiding the need for the creation of transgenic bacterial strains. By combining artificial root exudate medium, plant cultivation medium, and a synthetic bacterial community (SynCom), we first simulate their interactions using genome-scale metabolic models (GSMMs) and then validate these interactions in vitro, using growth assays. We show that the GSMM-predicted interaction scores correlate moderately, yet significantly, with their in vitro validation. Given the complexity of interactions among rhizosphere microbiome members, this reproducible and efficient protocol will allow confident mapping of interactions of fluorescent Pseudomonas with other bacterial strains within the rhizosphere microbiome. Key features • This method builds upon the widely used MS-based gnotobiotic system for growing plants and a synthetic bacterial community (SynCom) for plant-microbe interaction studies. • It considers the chemical composition of plant growth media (MS) and root exudates to map bacterial interactions. • It provides a method to both predict and validate interactions of fluorescent Pseudomonas with other strains within a SynCom. • This method is scalable for any bacterial pair with distinguishing markers (e.g., fluorescence, antibiotic resistance).

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ESP Quick Facts

ESP Origins

In the early 1990's, Robert Robbins was a faculty member at Johns Hopkins, where he directed the informatics core of GDB — the human gene-mapping database of the international human genome project. To share papers with colleagues around the world, he set up a small paper-sharing section on his personal web page. This small project evolved into The Electronic Scholarly Publishing Project.

ESP Support

In 1995, Robbins became the VP/IT of the Fred Hutchinson Cancer Research Center in Seattle, WA. Soon after arriving in Seattle, Robbins secured funding, through the ELSI component of the US Human Genome Project, to create the original ESP.ORG web site, with the formal goal of providing free, world-wide access to the literature of classical genetics.

ESP Rationale

Although the methods of molecular biology can seem almost magical to the uninitiated, the original techniques of classical genetics are readily appreciated by one and all: cross individuals that differ in some inherited trait, collect all of the progeny, score their attributes, and propose mechanisms to explain the patterns of inheritance observed.

ESP Goal

In reading the early works of classical genetics, one is drawn, almost inexorably, into ever more complex models, until molecular explanations begin to seem both necessary and natural. At that point, the tools for understanding genome research are at hand. Assisting readers reach this point was the original goal of The Electronic Scholarly Publishing Project.

ESP Usage

Usage of the site grew rapidly and has remained high. Faculty began to use the site for their assigned readings. Other on-line publishers, ranging from The New York Times to Nature referenced ESP materials in their own publications. Nobel laureates (e.g., Joshua Lederberg) regularly used the site and even wrote to suggest changes and improvements.

ESP Content

When the site began, no journals were making their early content available in digital format. As a result, ESP was obliged to digitize classic literature before it could be made available. For many important papers — such as Mendel's original paper or the first genetic map — ESP had to produce entirely new typeset versions of the works, if they were to be available in a high-quality format.

ESP Help

Early support from the DOE component of the Human Genome Project was critically important for getting the ESP project on a firm foundation. Since that funding ended (nearly 20 years ago), the project has been operated as a purely volunteer effort. Anyone wishing to assist in these efforts should send an email to Robbins.

ESP Plans

With the development of methods for adding typeset side notes to PDF files, the ESP project now plans to add annotated versions of some classical papers to its holdings. We also plan to add new reference and pedagogical material. We have already started providing regularly updated, comprehensive bibliographies to the ESP.ORG site.

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Papers in Classical Genetics

The ESP began as an effort to share a handful of key papers from the early days of classical genetics. Now the collection has grown to include hundreds of papers, in full-text format.

Digital Books

Along with papers on classical genetics, ESP offers a collection of full-text digital books, including many works by Darwin and even a collection of poetry — Chicago Poems by Carl Sandburg.

Timelines

ESP now offers a large collection of user-selected side-by-side timelines (e.g., all science vs. all other categories, or arts and culture vs. world history), designed to provide a comparative context for appreciating world events.

Biographies

Biographical information about many key scientists (e.g., Walter Sutton).

Selected Bibliographies

Bibliographies on several topics of potential interest to the ESP community are automatically maintained and generated on the ESP site.

ESP Picks from Around the Web (updated 28 JUL 2024 )