Stefanie Becker, Thu Trang Dang, Ran Wei, Andreas Kappler
{"title":"Evaluation of Thiobacillus denitrificans' sustainability in nitrate-reducing Fe(II) oxidation and the potential significance of Fe(II) as a growth-supporting reductant.","authors":"Stefanie Becker, Thu Trang Dang, Ran Wei, Andreas Kappler","doi":"10.1093/femsec/fiaf024","DOIUrl":"10.1093/femsec/fiaf024","url":null,"abstract":"<p><p>The betaproteobacterium Thiobacillus denitrificans (ATCC 25259) oxidizes Fe(II) while reducing nitrate, yet its capacity for autotrophic growth as a nitrate-reducing Fe(II)-oxidizer remains uncertain. This study explored this capacity through cultivation experiments across multiple transfers, using growth medium with Fe(II) and nitrate as sole electron donor and acceptor, respectively. This setup necessitated nitrate reduction coupled to Fe(II) oxidation as the primary energy-yielding mechanism and Fe(II) as the exclusive electron donor for CO2 fixation and biomass production. Thiosulfate/nitrate pregrown T. denitrificans oxidized 42% of 10 mM Fe(II), reduced 54% of 3.5 mM nitrate, and accumulated 1.6 mM nitrite, but showed no cell growth. Subsequent transfers from this Fe(II)/nitrate culture to fresh medium with Fe(II) and nitrate showed no nitrate-reducing Fe(II) oxidation or population growth. While bacterial activity [Fe(II) oxidation, nitrate reduction] occurred in the first transfer from thiosulfate/nitrate to Fe(II)/nitrate, nitrite was produced, further reacting with Fe(II) abiotically (chemodenitrification). A kinetic model assessed enzymatic versus abiotic Fe(II) oxidation, revealing enzymatic oxidation accounted for twice as much (ca. 70%) as abiotic denitrification (ca. 30%) within 22 days. These findings suggest T. denitrificans performs the first step of denitrification with Fe(II) as an electron donor but does not achieve autotrophic growth under these conditions.</p>","PeriodicalId":12312,"journal":{"name":"FEMS microbiology ecology","volume":" ","pages":""},"PeriodicalIF":3.5,"publicationDate":"2025-03-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11963766/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143647863","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Meaghan Castledine, Daniel Padfield, Rai Lewis, Angus Buckling
{"title":"Microbial community structure is affected by phage-resistance associated increases in host density.","authors":"Meaghan Castledine, Daniel Padfield, Rai Lewis, Angus Buckling","doi":"10.1093/femsec/fiaf027","DOIUrl":"10.1093/femsec/fiaf027","url":null,"abstract":"<p><p>Lytic bacteriophages ('phages') can limit bacterial densities and shape community structure, either directly through lysis or indirectly through costs to resistance. However, phages have also been reported to have no, and in some cases even positive, effects on host densities. Here, we investigate the mechanisms behind an increase in host density in Variovorax sp. populations following a fixation of resistance that was maintained after phage extinction. Our results demonstrate that the density increase was a genetic trait coinciding with resistance emergence. Growth curves showed that phage resistance shifted population growth curves such that density was higher in the death phase. This density-increasing effect of resistance had important implications for community structure with phage-resistant Variovorax decreasing the density of a conspecific. That resistance to lytic phage can increase host densities has implications for wider ecology and phage therapy, where lytic phages are presumed to have negative effects on their hosts.</p>","PeriodicalId":12312,"journal":{"name":"FEMS microbiology ecology","volume":" ","pages":""},"PeriodicalIF":3.5,"publicationDate":"2025-03-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11953036/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143656603","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Elisabeth Williamson, Kelly Hill, Katja Hogendoorn, Raphael Eisenhofer
{"title":"The bacterial community associated with the solitary resin bee Megachile tosticauda throughout its life cycle.","authors":"Elisabeth Williamson, Kelly Hill, Katja Hogendoorn, Raphael Eisenhofer","doi":"10.1093/femsec/fiaf023","DOIUrl":"10.1093/femsec/fiaf023","url":null,"abstract":"<p><p>Unlike in eusocial bees where the identity, acquisition, and function of symbiotic microbes are well understood, little is known about the relationships formed between solitary bees and bacteria. Assessing the potential role of microbes in solitary bee health is important, especially in the face of global bee declines. Early evidence suggests solitary bee microbiomes differ between bee species and development stages, but the reported bacteria are often indistinguishable from environmental taxa. Here, we use metabarcoding of the 16S rRNA gene to characterize the bacterial communities associated with solitary resin bee Megachile tosticauda. We describe the microbiome at different life cycle stages, and within pollen provisions, and investigate indirect inheritance from nesting substrate upon eclosion. The microbiome of adult M. tosticauda was consistent between samples, and the bacterial composition of larval pollen supplies changed with progressing larval development. In wild adults and pollen provisions, the genus Acinetobacter-a common nectar associate-dominated the communities. In prepupae and frass, Tyzzerella dominated, a genus that has been found in a number of other immature bee systems. Intriguingly, while wild adults did not harbour Tyzzerella, all bees that had newly emerged from the nest did. The combined observations show that M. tosticauda acquire their bacterial community from the environment, and Tyzzerella may represent a beneficial symbiont for mature brood.</p>","PeriodicalId":12312,"journal":{"name":"FEMS microbiology ecology","volume":" ","pages":""},"PeriodicalIF":3.5,"publicationDate":"2025-03-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11916890/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143556166","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Jingyi Xiao, Sijia Hao, Li-Juan Xiao, Yang Yang, Qinglong L Wu, Dan He, Lijun Zhou, Ren Hu, Lijuan Ren
{"title":"Particle-attached bacterial communities are more susceptible to seasonal environmental fluctuations in mesotrophic than eutrophic tropical reservoirs.","authors":"Jingyi Xiao, Sijia Hao, Li-Juan Xiao, Yang Yang, Qinglong L Wu, Dan He, Lijun Zhou, Ren Hu, Lijuan Ren","doi":"10.1093/femsec/fiae154","DOIUrl":"10.1093/femsec/fiae154","url":null,"abstract":"<p><p>Particle-attached bacterial (PAB) communities play pivotal roles in water organic matter decomposition, nutrient cycling, and the natural self-purification processes. However, we know little about their responses to seasonal environmental fluctuations, under eutrophication in reservoir ecosystems. In this study, we studied the shifts of PAB communities to seasonal environmental fluctuations in tropical China. Trophic state index (TSI) indicated that the studied reservoirs ranged from mesotrophic to eutrophic state with a gradual increase in TSI from 31 to 58. In eutrophic reservoirs, Cyanobacteria, especially Raphidiopsis raciborskii, significantly increased in its relative abundance from the wet to dry season, but Synechococcales and Microcystaceae decreased. In contrast, the relative abundance of Clostridia, Bacilli, Coriobacteriia, Enterobacteriales, and Vibrionales were more susceptible to seasonal environmental fluctuations in mesotrophic than eutrophic reservoirs. PAB co-occurrence relationships in mesotrophic reservoirs varied more greatly in response to seasonal environmental fluctuations, compared with eutrophic reservoirs, in terms of topological properties of connectedness, average degree, robustness, and vulnerability. Our results further demonstrated that the seasonal stability of PAB co-occurrence relationships was strongly correlative with TSI through mediating key bacterial taxa and community biodiversity. We proposed that eutrophication dramatically reduced the seasonal variation of PAB community compositions and co-occurring relationships in reservoir ecosystems.</p>","PeriodicalId":12312,"journal":{"name":"FEMS microbiology ecology","volume":" ","pages":""},"PeriodicalIF":3.5,"publicationDate":"2025-03-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11925149/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142603871","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Martha F Endika, David J M Barnett, Emiliana M Olmos, Cajo J F Ter Braak, Ilja C W Arts, John Penders, Arjen Nauta, Hans Leemhuis, Koen Venema, Hauke Smidt
{"title":"Assessing the potential for non-digestible carbohydrates toward mitigating adverse effects of antibiotics on microbiota composition and activity in an in vitro colon model of the weaning infant.","authors":"Martha F Endika, David J M Barnett, Emiliana M Olmos, Cajo J F Ter Braak, Ilja C W Arts, John Penders, Arjen Nauta, Hans Leemhuis, Koen Venema, Hauke Smidt","doi":"10.1093/femsec/fiaf028","DOIUrl":"10.1093/femsec/fiaf028","url":null,"abstract":"<p><p>Environmental factors like diet and antibiotics modulate the gut microbiota in early life. During weaning, gut microbiota progressively diversifies through exposure to non-digestible carbohydrates (NDCs) from diet, while antibiotic perturbations might disrupt this process. Supplementing an infant's diet with prebiotic NDCs may mitigate the adverse effects of antibiotics on gut microbiota development. This study evaluated the influence of supplementation with 2-fucosyllactose (2'-FL), galacto-oligosaccharides (GOS), or isomalto/malto-polysaccharides containing 87% of α(1→6) linkages (IMMP-87), on the recovery of antibiotic-perturbed microbiota. The TIM-2 in vitro colon model inoculated with fecal microbiota of 9-month-old infants was used to simulate the colon of weaning infants exposed to the antibiotics amoxicillin/clavulanate or azithromycin. Both antibiotics induced changes in microbiota composition, with no signs of recovery in azithromycin-treated microbiota within 72 h. Moreover, antibiotic exposure affected microbiota activity, indicated by a low valerate production, and azithromycin treatment was associated with increased succinate production. The IMMP-87 supplementation promoted the compositional recovery of amoxicillin/clavulanate-perturbed microbiota, associated with the recovery of Ruminococcus, Ruminococcus gauvreauii group, and Holdemanella. NDC supplementation did not influence compositional recovery of azithromycin-treated microbiota. Irrespective of antibiotic exposure, supplementation with 2'-FL, GOS, or IMMP-87 enhanced microbiota activity by increasing short-chain fatty acids production (acetate, propionate, and butyrate).</p>","PeriodicalId":12312,"journal":{"name":"FEMS microbiology ecology","volume":" ","pages":""},"PeriodicalIF":3.5,"publicationDate":"2025-03-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11963755/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143669151","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Plipastatin is a shared good by Bacillus subtilis during combating Fusarium spp.","authors":"Rune Overlund Stannius, Ákos T Kovács","doi":"10.1093/femsec/fiaf020","DOIUrl":"10.1093/femsec/fiaf020","url":null,"abstract":"<p><p>Bacillus subtilis a Gram-positive soil-dwelling bacterium known for its wide range of bioactive secondary metabolites. The lipopeptide plipastatin produced by most B. subtilis isolates have been shown to exhibit potent antifungal activity against plant pathogenic fungi. While the effect of these antifungal compounds are well studied in the context of biocontrol, much less is known of their role in the environment, which also harbor nonproducing strains of these compounds. Fusarium species produce multiple antibacterial compounds resulting in dysbiosis of the plant-associated microbiome and inhibition of plant beneficial bacteria like B. subtilis. While plipastatin is expected to be important for survival of B. subtilis, not all isolates carry the biosynthetic gene cluster for plipastatin suggesting that the protective effect of plipastatin might be shared. In this study, we investigated the protective effect of plipastatin against Fusarium oxysporum in a coculture using a producer and a nonproducer isolate of plipastatin. We tested the survival of single and cocultured strains under Fusarium challenge in liquid media and solid agar plates to dissect the influence of spatial structure. Our results highlights that plipastatin protects the nonproducer strain in a density-dependent manner.</p>","PeriodicalId":12312,"journal":{"name":"FEMS microbiology ecology","volume":" ","pages":""},"PeriodicalIF":3.5,"publicationDate":"2025-03-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11916886/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143499223","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Valentin Barberoux, Adriana Anzil, Loïc Meinertzhagen, Thanh Nguyen-Dinh, Pierre Servais, Isabelle F George
{"title":"Spatio-temporal dynamics of bacterial community composition in a Western European watershed, the Meuse River watershed.","authors":"Valentin Barberoux, Adriana Anzil, Loïc Meinertzhagen, Thanh Nguyen-Dinh, Pierre Servais, Isabelle F George","doi":"10.1093/femsec/fiaf022","DOIUrl":"10.1093/femsec/fiaf022","url":null,"abstract":"<p><p>This study aimed to identify factors influencing bacterial diversity in the Meuse River watershed by analyzing 42 locations sampled in spring and summer 2019, combined with biweekly sampling of one mid-stream location for a year. Bacterial community composition (BCC) was assessed in the small (SF; <5 µm) and large fractions (LF; ≥5 µm,), alongside physico-chemical parameters. LF consistently exhibited greater alpha diversity than SF. During the spatial campaigns, alpha diversity increased downstream in spring with high discharge, and BCC differed significantly between headwaters and the main river. Along this axis, several genera, Flavobacterium, Limnohabitans, and Aquirufa stood out as indicators of good water quality. Rhodoferax, another taxon indicative of good water quality, prevailed in the headwaters and during winter. In contrast, two cyanobacteria genera indicators of poor river quality, Microcystis PCC 7914 and Cyanobium PCC 6307, peaked in summer. BCC in spring and summer temporal samples aligned with spatial ones, while winter and autumn samples had distinct BCC. Finally, season, temperature, and distance from river mouth were the main driving parameters of beta diversity, outweighing the effect of fraction size on the BCC. These findings reinforce the notion that local conditions exert significant influence on bacterial communities in rivers.</p>","PeriodicalId":12312,"journal":{"name":"FEMS microbiology ecology","volume":" ","pages":""},"PeriodicalIF":3.5,"publicationDate":"2025-03-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11916896/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143566530","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Giuliano Bonanomi, Giuseppina Iacomino, Luigi Di Costanzo, Mauro Moreno, Giulio Tesei, Marina Allegrezza, Stefano Mazzoleni, Mohamed Idbella
{"title":"Mechanisms and impacts of Agaricus urinascens fairy rings on plant diversity and microbial communities in a montane Mediterranean grassland.","authors":"Giuliano Bonanomi, Giuseppina Iacomino, Luigi Di Costanzo, Mauro Moreno, Giulio Tesei, Marina Allegrezza, Stefano Mazzoleni, Mohamed Idbella","doi":"10.1093/femsec/fiaf034","DOIUrl":"10.1093/femsec/fiaf034","url":null,"abstract":"<p><p>Fungal fairy rings (FFRs) significantly influence plant communities and soil microbiota. This study investigated the development of Agaricus urinascens fairy rings in a species-rich montane Mediterranean grassland. By combining vegetation analysis, soil chemistry measurements, and next-generation sequencing, we assessed fairy rings' impact on soil properties, plants, fungi, and bacteria. Our findings reveal a fungal-driven transformation of biological communities, with significant variations across FFRs zones. At the fungal front (FF), plant biomass decreased slightly but increased more than threefold inside the ring (>1100 g m-2), favouring grasses like Brachypodium genuense over forbs. In addition, species richness dropped significantly in the FF (-40%) compared to surrounding grassland, particularly affecting perennials. Moreover, our findings reveal substantial alterations in soil properties at the FF, including a 534% increase in P₂O5, a 210% rise in electrical conductivity, and a 36% increase in soil hydrophobicity compared to the surrounding grassland. Clay content at the FF was nearly three times higher than outside the ring (162.8 versus 57.5 g kg-1), indicating potential structural modifications in the soil matrix. Organic carbon decreased by 10% in the FF, while the C/N ratio and cation exchange capacity dropped significantly. Distinct shifts in microbial composition were observed. Bacterial diversity declined at the FF, where Actinobacteria dominated (85%) and Proteobacteria dropped to 8%. Similarly, fungal diversity was lowest inside the ring but highest in the belt section, with Ascomycota reaching 97% at the FF. Certain taxa, such as Kribbella, Streptomyces, Trichoderma, Penicillium, and Dichotomopilus, coexisted with A. urinascens mycelium. Notably, hydrophobicity at the FF was linked to high calcium oxalate crystal coverage on fungal mycelium and plant roots. This may have accelerated root desiccation, ultimately leading to plant mortality. Overall, our findings provide strong evidence that fairy ring fungi act as ecosystem engineers, shaping the spatial patterns of biotic composition and diversity in Mediterranean grasslands.</p>","PeriodicalId":12312,"journal":{"name":"FEMS microbiology ecology","volume":" ","pages":""},"PeriodicalIF":3.5,"publicationDate":"2025-03-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11983688/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143763340","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Dominika Klimek, Malte Herold, Inês Rosado Vitorino, Zuzana Dedova, Sebastien Lemaigre, Jimmy Roussel, Xavier Goux, Olga Maria Lage, Magdalena Calusinska
{"title":"Insights into the phylogenetic and metabolic diversity of Planctomycetota in anaerobic digesters and the isolation of novel Thermoguttaceae species.","authors":"Dominika Klimek, Malte Herold, Inês Rosado Vitorino, Zuzana Dedova, Sebastien Lemaigre, Jimmy Roussel, Xavier Goux, Olga Maria Lage, Magdalena Calusinska","doi":"10.1093/femsec/fiaf025","DOIUrl":"10.1093/femsec/fiaf025","url":null,"abstract":"<p><p>Studying bacteria in anaerobic digestion (AD) is crucial for optimizing microbial processes. While abundant taxa are often studied, less abundant groups may harbour novel metabolic potential. This study fills the gap by focusing on the Planctomycetota phylum, known to encode diverse carbohydrate-active enzymes (CAZymes). Despite their common presence in diverse aerobic and anaerobic environments, their role in AD is relatively unexplored. We utilized both culture-dependent and culture-independent techniques to investigate the phylogenetic and metabolic diversity of Planctomycetota within AD reactors. Our findings revealed that among the diverse planctomycetotal operational taxonomic units present, only a few are prevalent and abundant community members. Planctomycetota share functional traits with e.g. Verrucomicrobiota exhibiting distinct CAZyme gene repertoires that indicates specialization in degrading algal polysaccharides and glycoproteins. To explore the planctomycetotal metabolic capabilities, we monitored their presence in algal-fed digesters. Additionally, we isolated a strain from mucin-based medium, revealing its genetic potential for a mixotrophic lifestyle. Based on the genomic analysis, we propose to introduce the Candidatus Luxemburgiella decessa gen. nov. sp. nov., belonging to the Thermoguttaceae family within the Pirellulales order of the Planctomycetia class. This study enhances our understanding of Planctomycetota in AD by highlighting their phylogenetic diversity and metabolic capabilities.</p>","PeriodicalId":12312,"journal":{"name":"FEMS microbiology ecology","volume":" ","pages":""},"PeriodicalIF":3.5,"publicationDate":"2025-03-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11929135/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143647864","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}