Zaki Saati-Santamaría, Pilar Navarro-Gómez, Juan A Martínez-Mancebo, Maitane Juárez-Mugarza, Amando Flores, Inés Canosa
Genomic reorganisation between species and horizontal gene transfer have been considered the most important mechanism of biological adaptation under selective pressure. Still, the impact of mobile genes in microbial ecology is far from being completely understood. Here we present the collection and characterisation of microbial consortia enriched from environments contaminated with emerging pollutants, such as non-steroidal anti-inflammatory drugs. We have obtained and further enriched two ibuprofen-degrading microbial consortia from two unrelated wastewater treatment plants. We have also studied their ability to degrade the drug and the dynamics of the reorganisations of the genetic information responsible for its biodegradation among the species within the consortium. Our results show that genomic reorganisation within microorganisms and species rearrangements occur rapidly and efficiently during the selection process, which may be facilitated by plasmids and/or transposable elements located within the sequences. We show the evolution of at least two different plasmid backbones on samples from different locations, showing rearrangements of genomic information, including genes encoding activities for IBU degradation. As a result, we found variations in the expression pattern of the consortia after evolution under selective pressure, as an adaptation process to the new conditions. This work provides evidence for changes in the metagenomes of microbial communities that allow adaptation under a selective constraint –ibuprofen as a sole carbon source– and represents a step forward in knowledge that can inspire future biotechnological developments for drug bioremediation.
{"title":"Genetic and species rearrangements in microbial consortia impact biodegradation potential","authors":"Zaki Saati-Santamaría, Pilar Navarro-Gómez, Juan A Martínez-Mancebo, Maitane Juárez-Mugarza, Amando Flores, Inés Canosa","doi":"10.1093/ismejo/wraf014","DOIUrl":"https://doi.org/10.1093/ismejo/wraf014","url":null,"abstract":"Genomic reorganisation between species and horizontal gene transfer have been considered the most important mechanism of biological adaptation under selective pressure. Still, the impact of mobile genes in microbial ecology is far from being completely understood. Here we present the collection and characterisation of microbial consortia enriched from environments contaminated with emerging pollutants, such as non-steroidal anti-inflammatory drugs. We have obtained and further enriched two ibuprofen-degrading microbial consortia from two unrelated wastewater treatment plants. We have also studied their ability to degrade the drug and the dynamics of the reorganisations of the genetic information responsible for its biodegradation among the species within the consortium. Our results show that genomic reorganisation within microorganisms and species rearrangements occur rapidly and efficiently during the selection process, which may be facilitated by plasmids and/or transposable elements located within the sequences. We show the evolution of at least two different plasmid backbones on samples from different locations, showing rearrangements of genomic information, including genes encoding activities for IBU degradation. As a result, we found variations in the expression pattern of the consortia after evolution under selective pressure, as an adaptation process to the new conditions. This work provides evidence for changes in the metagenomes of microbial communities that allow adaptation under a selective constraint –ibuprofen as a sole carbon source– and represents a step forward in knowledge that can inspire future biotechnological developments for drug bioremediation.","PeriodicalId":516554,"journal":{"name":"The ISME Journal","volume":"139 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-01-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143031245","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Alexander B Alleman,Sergey Stolyar,Christopher J Marx,Jean-Baptiste Leducq
Although the 16S (and 18S) rRNA gene has been an essential tool in classifying prokaryotes, using a single locus to revise bacteria taxonomy can introduce unwanted artifacts. There was a recent proposition to split the Methylobacterium genus, which contains diverse plant-associated strains and is important for agriculture and biotechnology, into two genera. Resting strongly on the phylogeny of 16S rRNA, 11 species of Methylobacterium were transferred to a newly proposed genus Methylorubrum. Numerous recent studies have independently questioned Methylorubrum as a valid genus, but the prior revision has left discrepancies amongst taxonomic databases. Here, we review phylogenomic and phenotypic evidence against Methylorubrum as a genus and call for its abandonment. Because Methylobacterium sensu lato forms a consistent and monophyletic genus, we argue for the restoration of the former and consensual Methylobacterium taxonomy. The large genomic, phenotypic, and ecological diversity within Methylobacterium however suggests complex evolutionary and adaptive processes and support the description of the most basal clade of Methylobacterium (group C) as a distinct genus in future work. Overall, this perspective demonstrates the danger of solely relying upon the 16S rRNA gene as a delimiter of genus level taxonomy and that further attempts must include more robust phenotypic and phylogenomic criteria.
{"title":"Led astray by 16S rRNA: phylogenomics reaffirms the monophyly of Methylobacterium and lack of support for Methylorubrum as a genus.","authors":"Alexander B Alleman,Sergey Stolyar,Christopher J Marx,Jean-Baptiste Leducq","doi":"10.1093/ismejo/wraf011","DOIUrl":"https://doi.org/10.1093/ismejo/wraf011","url":null,"abstract":"Although the 16S (and 18S) rRNA gene has been an essential tool in classifying prokaryotes, using a single locus to revise bacteria taxonomy can introduce unwanted artifacts. There was a recent proposition to split the Methylobacterium genus, which contains diverse plant-associated strains and is important for agriculture and biotechnology, into two genera. Resting strongly on the phylogeny of 16S rRNA, 11 species of Methylobacterium were transferred to a newly proposed genus Methylorubrum. Numerous recent studies have independently questioned Methylorubrum as a valid genus, but the prior revision has left discrepancies amongst taxonomic databases. Here, we review phylogenomic and phenotypic evidence against Methylorubrum as a genus and call for its abandonment. Because Methylobacterium sensu lato forms a consistent and monophyletic genus, we argue for the restoration of the former and consensual Methylobacterium taxonomy. The large genomic, phenotypic, and ecological diversity within Methylobacterium however suggests complex evolutionary and adaptive processes and support the description of the most basal clade of Methylobacterium (group C) as a distinct genus in future work. Overall, this perspective demonstrates the danger of solely relying upon the 16S rRNA gene as a delimiter of genus level taxonomy and that further attempts must include more robust phenotypic and phylogenomic criteria.","PeriodicalId":516554,"journal":{"name":"The ISME Journal","volume":"22 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-01-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142991835","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Vincent Zieschank, Anne Muola, Stefan Janssen, Alexander Lach, Robert R Junker
Land-use changes threaten ecosystems and are a major driver of species loss. Plants may adapt or migrate to resist global change, but this can lag behind rapid anthropogenic changes to the environment. Our data show that natural modulations of the microbiome of grassland plants in response to experimental land-use change in a common garden directly affect plant phenotype and performance, thus increasing plant tolerance. In contrast, direct effects of fertilizer application and mowing on plant phenotypes were less strong. Land-use intensity-specific microbiomes caused clearly distinguishable plant phenotypes also in a laboratory experiment using gnotobiotic strawberry plants in absence of environmental variation. Therefore, natural modulations of the plant microbiome may be key to species persistence and ecosystem stability. We argue that a prerequisite for this microbiome-mediated tolerance is the availability of diverse local sources of microorganisms facilitating rapid modulations in response to change. Thus, conservation efforts must protect microbial diversity, which can help mitigate the effects of global change and facilitate environmental and human health.
{"title":"Tolerance to land-use changes through natural modulations of the plant microbiome","authors":"Vincent Zieschank, Anne Muola, Stefan Janssen, Alexander Lach, Robert R Junker","doi":"10.1093/ismejo/wraf010","DOIUrl":"https://doi.org/10.1093/ismejo/wraf010","url":null,"abstract":"Land-use changes threaten ecosystems and are a major driver of species loss. Plants may adapt or migrate to resist global change, but this can lag behind rapid anthropogenic changes to the environment. Our data show that natural modulations of the microbiome of grassland plants in response to experimental land-use change in a common garden directly affect plant phenotype and performance, thus increasing plant tolerance. In contrast, direct effects of fertilizer application and mowing on plant phenotypes were less strong. Land-use intensity-specific microbiomes caused clearly distinguishable plant phenotypes also in a laboratory experiment using gnotobiotic strawberry plants in absence of environmental variation. Therefore, natural modulations of the plant microbiome may be key to species persistence and ecosystem stability. We argue that a prerequisite for this microbiome-mediated tolerance is the availability of diverse local sources of microorganisms facilitating rapid modulations in response to change. Thus, conservation efforts must protect microbial diversity, which can help mitigate the effects of global change and facilitate environmental and human health.","PeriodicalId":516554,"journal":{"name":"The ISME Journal","volume":"6 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-01-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142992277","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Mathias Middelboe, Sachia J Traving, Daniel Castillo, Panos G Kalatzis, Ronnie N Glud
Auxiliary metabolic genes encoded by bacteriophages can influence host metabolic function during infection. In temperate phages, auxiliary metabolic genes may increase host fitness when integrated as prophages into the host genome. However, little is known about the contribution of prophage-encoded auxiliary metabolic genes to host metabolic properties. In this study, we examined a temperate bacteriophage, and its piezotolerant Pseudomonas sp. host obtained from sediment samples collected from the Kermadec Trench at ~10 000 m water depth. Both the phage and host were present throughout the sediment profiles from the surface to 30 cm into the sediment, covering large gradients of environmental conditions. The host and phage each carried one chitinase gene, which differed from each other, suggesting that chitin degradation plays a role in their substrate supply. We demonstrated that prophage-encoded chitinase supported host chitin degradation and growth in the presence of chitin. Furthermore, prophage induction dynamics were strongly substrate-dependent, suggesting that the host controls the lysis-lysogeny switch in response to the presence of chitin, thus optimizing the trade-off between the loss of cells from prophage induction and prophage enhancement of host performance. Overall, the results demonstrate prophage-encoded auxiliary metabolic genes as collaborative goods for their hosts and emphasize the potential role of phage-host interactions in benthic biogeochemical cycling, as well as for the capability of deep-sea bacteria to efficiently adapt and thrive at a wide range of environmental conditions.
{"title":"Prophage-encoded chitinase gene supports growth of its bacterial host isolated from deep-sea sediments","authors":"Mathias Middelboe, Sachia J Traving, Daniel Castillo, Panos G Kalatzis, Ronnie N Glud","doi":"10.1093/ismejo/wraf004","DOIUrl":"https://doi.org/10.1093/ismejo/wraf004","url":null,"abstract":"Auxiliary metabolic genes encoded by bacteriophages can influence host metabolic function during infection. In temperate phages, auxiliary metabolic genes may increase host fitness when integrated as prophages into the host genome. However, little is known about the contribution of prophage-encoded auxiliary metabolic genes to host metabolic properties. In this study, we examined a temperate bacteriophage, and its piezotolerant Pseudomonas sp. host obtained from sediment samples collected from the Kermadec Trench at ~10 000 m water depth. Both the phage and host were present throughout the sediment profiles from the surface to 30 cm into the sediment, covering large gradients of environmental conditions. The host and phage each carried one chitinase gene, which differed from each other, suggesting that chitin degradation plays a role in their substrate supply. We demonstrated that prophage-encoded chitinase supported host chitin degradation and growth in the presence of chitin. Furthermore, prophage induction dynamics were strongly substrate-dependent, suggesting that the host controls the lysis-lysogeny switch in response to the presence of chitin, thus optimizing the trade-off between the loss of cells from prophage induction and prophage enhancement of host performance. Overall, the results demonstrate prophage-encoded auxiliary metabolic genes as collaborative goods for their hosts and emphasize the potential role of phage-host interactions in benthic biogeochemical cycling, as well as for the capability of deep-sea bacteria to efficiently adapt and thrive at a wide range of environmental conditions.","PeriodicalId":516554,"journal":{"name":"The ISME Journal","volume":"13 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-01-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142991150","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Multi-species mutualistic interactions are ubiquitous and essential in nature, yet they face several threats, many of which have been exacerbated in the Anthropocene era. Understanding the factors that drive the stability and persistence of mutualism has become increasingly important in light of global change. Although dispersal is widely recognized as a crucial spatially explicit process in maintaining biodiversity and community structure, knowledge about how the dispersal of mutualists contributes to the persistence of mutualistic systems remains limited. In this study, we used a synthetic mutualism formed by genetically modified budding yeast to investigate the effect of dispersal on the persistence and stability of mutualisms under exploitation. We found that dispersal increased the persistence of exploited mutualisms by 80% compared to the isolated systems. Furthermore, our results showed that dispersal increased local diversity, decreased beta diversity among local communities, and stabilized community structure at the regional scale. Our results indicate that dispersal can allow mutualisms to persist in meta-communities by reintroducing species that are locally competitively excluded by exploiters. With limited dispersal, e.g., due to increased fragmentation of meta-communities, mutualisms might be more prone to breakdown. Taken together, our results highlight the critical role of dispersal in facilitating the persistence of mutualism.
{"title":"Dispersal promotes stability and persistence of exploited yeast mutualisms","authors":"Cong Liu, Mayra C Vidal","doi":"10.1093/ismejo/wraf003","DOIUrl":"https://doi.org/10.1093/ismejo/wraf003","url":null,"abstract":"Multi-species mutualistic interactions are ubiquitous and essential in nature, yet they face several threats, many of which have been exacerbated in the Anthropocene era. Understanding the factors that drive the stability and persistence of mutualism has become increasingly important in light of global change. Although dispersal is widely recognized as a crucial spatially explicit process in maintaining biodiversity and community structure, knowledge about how the dispersal of mutualists contributes to the persistence of mutualistic systems remains limited. In this study, we used a synthetic mutualism formed by genetically modified budding yeast to investigate the effect of dispersal on the persistence and stability of mutualisms under exploitation. We found that dispersal increased the persistence of exploited mutualisms by 80% compared to the isolated systems. Furthermore, our results showed that dispersal increased local diversity, decreased beta diversity among local communities, and stabilized community structure at the regional scale. Our results indicate that dispersal can allow mutualisms to persist in meta-communities by reintroducing species that are locally competitively excluded by exploiters. With limited dispersal, e.g., due to increased fragmentation of meta-communities, mutualisms might be more prone to breakdown. Taken together, our results highlight the critical role of dispersal in facilitating the persistence of mutualism.","PeriodicalId":516554,"journal":{"name":"The ISME Journal","volume":"16 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-01-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142939659","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Amanda N Shelton, Feiqiao B Yu, Arthur R Grossman, Devaki Bhaya
Photosynthetic microbial mats in hot springs can provide insights into the diel behaviors of communities in extreme environments. In this habitat, photosynthesis dominates during the day, leading to super-oxic conditions, with a rapid transition to fermentation and anoxia at night. Multiple samples were collected from two springs over several years to generate metagenomic and metatranscriptomic datasets. Metagenome assembled genomes comprised 71 taxa (in 19 different phyla), of which twelve core taxa were present at high abundance in both springs. The eight most active taxa identified by metatranscriptomics were an oxygenic cyanobacterium (Synechococcus sp.), five anoxygenic phototrophs from three different phyla, and two understudied heterotrophs from phylum Armatimonadota. In all eight taxa, a significant fraction of genes exhibited a diel expression pattern although peak timing varied considerably. The two abundant heterotrophs exhibit starkly different peak timing of expression, which we propose is shaped by their metabolic and genomic potential to use carbon sources that become differentially available during the diel cycle. Network analysis revealed pathway expression patterns that had not previously been linked to diel cycles, including ribosome biogenesis and chaperones. This provides a framework for analyzing metabolically coupled communities and the dominant role of the diel cycle.
{"title":"Abundant and active community members respond to diel cycles in hot spring phototrophic mats","authors":"Amanda N Shelton, Feiqiao B Yu, Arthur R Grossman, Devaki Bhaya","doi":"10.1093/ismejo/wraf001","DOIUrl":"https://doi.org/10.1093/ismejo/wraf001","url":null,"abstract":"Photosynthetic microbial mats in hot springs can provide insights into the diel behaviors of communities in extreme environments. In this habitat, photosynthesis dominates during the day, leading to super-oxic conditions, with a rapid transition to fermentation and anoxia at night. Multiple samples were collected from two springs over several years to generate metagenomic and metatranscriptomic datasets. Metagenome assembled genomes comprised 71 taxa (in 19 different phyla), of which twelve core taxa were present at high abundance in both springs. The eight most active taxa identified by metatranscriptomics were an oxygenic cyanobacterium (Synechococcus sp.), five anoxygenic phototrophs from three different phyla, and two understudied heterotrophs from phylum Armatimonadota. In all eight taxa, a significant fraction of genes exhibited a diel expression pattern although peak timing varied considerably. The two abundant heterotrophs exhibit starkly different peak timing of expression, which we propose is shaped by their metabolic and genomic potential to use carbon sources that become differentially available during the diel cycle. Network analysis revealed pathway expression patterns that had not previously been linked to diel cycles, including ribosome biogenesis and chaperones. This provides a framework for analyzing metabolically coupled communities and the dominant role of the diel cycle.","PeriodicalId":516554,"journal":{"name":"The ISME Journal","volume":"31 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-01-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142937341","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Camille C Mangin, Karim Benzerara, Marine Bergot, Nicolas Menguy, Béatrice Alonso, Stéphanie Fouteau, Raphaël Méheust, Daniel Chevrier, Christian Godon, Elsa Turrini, Neha Mehta, Arnaud Duverger, Cynthia Travert, Vincent Busigny, Elodie Duprat, Romain Bolzoni, Corinne Cruaud, Eric Viollier, Didier Jézéquel, David Vallenet, Christopher T Lefèvre, Caroline L Monteil
Intracellular calcium carbonate formation has long been associated with a single genus of giant Gammaproteobacteria, Achromatium. However, this biomineralization has recently received increasing attention after being observed in photosynthetic Cyanobacteriota and in two families of magnetotactic bacteria affiliated with the Alphaproteobacteria. In the latter group, bacteria form not only intracellular amorphous calcium carbonates into large inclusions that are refringent under the light microscope, but also intracellular ferrimagnetic crystals into organelles called magnetosomes. Here new observations suggest that magnetotactic bacteria previously identified in the sediments and water column of Lake Pavin (France) were only a small fraction of the diversity of bacteria producing intracellular amorphous calcium carbonates. To explore this diversity further, we conducted a comprehensive investigation of magnetotactic populations with refractive granules using a combination of environmental microbiology, genomic and mineralogy approaches on cells sorted by micromanipulation. Several species belonging to divergent genera of two Pseudomonadota classes were identified and characterized. Scanning transmission electron microscopy coupled with energy-dispersive X-ray spectrometry support that all these species indeed form intracellular amorphous calcium carbonates. Cryo soft X-ray tomography experiments conducted on ice-vitrified cells, enabled 3D investigation of inclusions volume, which was found to occupy 44 – 68% of the cell volume. Metabolic network modeling highlighted different metabolic abilities of Alpha- and Gammaproteobacteria, including methylotrophy and CO2 fixation via the reverse Krebs cycle or the Calvin-Benson-Bassham cycle. Overall, this study strengthens a convergent evolution scenario for intracellular carbonatogenesis in Bacteria, and further supports that it is promoted by the fixation of CO2 in anoxic environments.
{"title":"Magnetotactic bacteria from diverse Pseudomonadota families biomineralize intracellular Ca-carbonate","authors":"Camille C Mangin, Karim Benzerara, Marine Bergot, Nicolas Menguy, Béatrice Alonso, Stéphanie Fouteau, Raphaël Méheust, Daniel Chevrier, Christian Godon, Elsa Turrini, Neha Mehta, Arnaud Duverger, Cynthia Travert, Vincent Busigny, Elodie Duprat, Romain Bolzoni, Corinne Cruaud, Eric Viollier, Didier Jézéquel, David Vallenet, Christopher T Lefèvre, Caroline L Monteil","doi":"10.1093/ismejo/wrae260","DOIUrl":"https://doi.org/10.1093/ismejo/wrae260","url":null,"abstract":"Intracellular calcium carbonate formation has long been associated with a single genus of giant Gammaproteobacteria, Achromatium. However, this biomineralization has recently received increasing attention after being observed in photosynthetic Cyanobacteriota and in two families of magnetotactic bacteria affiliated with the Alphaproteobacteria. In the latter group, bacteria form not only intracellular amorphous calcium carbonates into large inclusions that are refringent under the light microscope, but also intracellular ferrimagnetic crystals into organelles called magnetosomes. Here new observations suggest that magnetotactic bacteria previously identified in the sediments and water column of Lake Pavin (France) were only a small fraction of the diversity of bacteria producing intracellular amorphous calcium carbonates. To explore this diversity further, we conducted a comprehensive investigation of magnetotactic populations with refractive granules using a combination of environmental microbiology, genomic and mineralogy approaches on cells sorted by micromanipulation. Several species belonging to divergent genera of two Pseudomonadota classes were identified and characterized. Scanning transmission electron microscopy coupled with energy-dispersive X-ray spectrometry support that all these species indeed form intracellular amorphous calcium carbonates. Cryo soft X-ray tomography experiments conducted on ice-vitrified cells, enabled 3D investigation of inclusions volume, which was found to occupy 44 – 68% of the cell volume. Metabolic network modeling highlighted different metabolic abilities of Alpha- and Gammaproteobacteria, including methylotrophy and CO2 fixation via the reverse Krebs cycle or the Calvin-Benson-Bassham cycle. Overall, this study strengthens a convergent evolution scenario for intracellular carbonatogenesis in Bacteria, and further supports that it is promoted by the fixation of CO2 in anoxic environments.","PeriodicalId":516554,"journal":{"name":"The ISME Journal","volume":"30 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-01-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142935980","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The intestinal microbiota plays a critical role in maintaining human health and can be modulated by dietary interventions and lifestyle choices. Fructans, a dietary carbohydrate, are selectively utilized by the intestinal microbiota to confer health benefits. However, the specific effects of different fructan types on microbial changes and functions remain incompletely understood. Here, we investigated how the intestinal microbiota responds to fructans with varying degrees of polymerization in the context of gut dysbiosis. Both low molecular weight fructo-oligosaccharides and high molecular weight levan suppressed intestinal inflammation in a colitis mouse model, mitigating intestinal fibrosis and dysbiosis. Although both the effects of fructo-oligosaccharides and levan are microbiota-dependent, distinct modulation patterns of the intestinal microbiota were observed based on the molecular weight of the fructans. Levan had a more pronounced and persistent impact on gut microbiota compared to fructo-oligosaccharides. Levan particularly promoted the abundance of Dubosiella newyorkensis, which exhibited preventive effects against colitis. Our findings highlight the importance of polymerization levels of dietary fructans in microbiota alterations and identify Dubosiella newyorkensis as a potential probiotic for treating inflammatory diseases.
{"title":"Polymerization of dietary fructans differentially affects interactions among intestinal microbiota of colitis mice","authors":"Yaqin Xiao, Qianyun Zhao, Dawei Ni, Xiaoqi Zhang, Wei Hao, Qin Yuan, Wei Xu, Wanmeng Mu, Dingtao Wu, Xu Wu, Shengpeng Wang","doi":"10.1093/ismejo/wrae262","DOIUrl":"https://doi.org/10.1093/ismejo/wrae262","url":null,"abstract":"The intestinal microbiota plays a critical role in maintaining human health and can be modulated by dietary interventions and lifestyle choices. Fructans, a dietary carbohydrate, are selectively utilized by the intestinal microbiota to confer health benefits. However, the specific effects of different fructan types on microbial changes and functions remain incompletely understood. Here, we investigated how the intestinal microbiota responds to fructans with varying degrees of polymerization in the context of gut dysbiosis. Both low molecular weight fructo-oligosaccharides and high molecular weight levan suppressed intestinal inflammation in a colitis mouse model, mitigating intestinal fibrosis and dysbiosis. Although both the effects of fructo-oligosaccharides and levan are microbiota-dependent, distinct modulation patterns of the intestinal microbiota were observed based on the molecular weight of the fructans. Levan had a more pronounced and persistent impact on gut microbiota compared to fructo-oligosaccharides. Levan particularly promoted the abundance of Dubosiella newyorkensis, which exhibited preventive effects against colitis. Our findings highlight the importance of polymerization levels of dietary fructans in microbiota alterations and identify Dubosiella newyorkensis as a potential probiotic for treating inflammatory diseases.","PeriodicalId":516554,"journal":{"name":"The ISME Journal","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-01-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142917183","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In this study, we identify and characterize a novel phage-inducible chromosomal island found in commensal Escherichia coli MP1. This novel element, EcCIMP1, is induced and mobilized by the temperate helper phage vB_EcoP_Kapi1. EcCIMP1 contributes to superinfection immunity against its helper phage, impacting bacterial competition outcomes. Genetic analysis of EcCIMP1 led us to uncover a putative transcriptional repressor, which silences virulence gene expression in the murine pathogen Citrobacter rodentium. We also found a putative excisionase encoded by EcCIMP1 which paradoxically does not promote excision of EcCIMP1, but rather supports excision of the helper phage. Another putative excisionase encoded by a presumed integrative conjugative element can also support excision of vB_EcoP_Kapi1, demonstrating crosstalk between excisionases from multiple classes of mobile genetic elements within the same cell. Although phylogenetically distant from other characterized phage-inducible chromosomal islands, EcCIMP1 and EcCIMP1-like elements are prevalent in both pathogenic and commensal isolates of Escherchia coli from around the world, underscoring the importance of characterizing these abundant genetic elements.
{"title":"Escherichia coli phage-inducible chromosomal island aids helper phage replication and represses the LEE pathogenicity island","authors":"Kat Pick, Lauren Stadel, Tracy L Raivio","doi":"10.1093/ismejo/wrae258","DOIUrl":"https://doi.org/10.1093/ismejo/wrae258","url":null,"abstract":"In this study, we identify and characterize a novel phage-inducible chromosomal island found in commensal Escherichia coli MP1. This novel element, EcCIMP1, is induced and mobilized by the temperate helper phage vB_EcoP_Kapi1. EcCIMP1 contributes to superinfection immunity against its helper phage, impacting bacterial competition outcomes. Genetic analysis of EcCIMP1 led us to uncover a putative transcriptional repressor, which silences virulence gene expression in the murine pathogen Citrobacter rodentium. We also found a putative excisionase encoded by EcCIMP1 which paradoxically does not promote excision of EcCIMP1, but rather supports excision of the helper phage. Another putative excisionase encoded by a presumed integrative conjugative element can also support excision of vB_EcoP_Kapi1, demonstrating crosstalk between excisionases from multiple classes of mobile genetic elements within the same cell. Although phylogenetically distant from other characterized phage-inducible chromosomal islands, EcCIMP1 and EcCIMP1-like elements are prevalent in both pathogenic and commensal isolates of Escherchia coli from around the world, underscoring the importance of characterizing these abundant genetic elements.","PeriodicalId":516554,"journal":{"name":"The ISME Journal","volume":"28 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-01-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142917578","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Microbial communities thrive in virtually every habitat on Earth and are essential to the function of diverse ecosystems. Most microbial habitats are not spatially continuous and well-mixed, but rather composed, at the microscale, of many isolated or semi-isolated local patches of different sizes, resulting in partitioning of microbial populations into discrete local populations. The impact of this spatial fragmentation on population dynamics is not well-understood. Here, we study how such variably sized micro-habitat patches affect the growth dynamics of clonal microbial populations and how dynamics in individual patches dictate those of the metapopulation. To investigate this, we developed the μ-SPLASH, an ecology-on-a-chip platform, enabling the culture of microbes in microscopic landscapes comprised of thousands of microdroplets, with a wide range of sizes. Using the μ-SPLASH, we cultured the model bacteria E. coli and based on time-lapse microscopy, analyzed the population dynamics within thousands of individual droplets. Our results reveal that growth curves substantially vary with droplet size. Although growth rates generally increase with drop size, reproductive success and the time to approach carrying capacity, display non-monotonic patterns. Combining μ-SPLASH experiments with computational modeling, we show that these patterns result from both stochastic and deterministic processes, and demonstrate the roles of initial population density, patchiness, and patch size distribution in dictating the local and metapopulation dynamics. This study reveals basic principles that elucidate the effects of habitat fragmentation and population partitioning on microbial population dynamics. These insights deepen our understanding of natural microbial communities and have significant implications for microbiome engineering.
{"title":"Impact of micro-habitat fragmentation on microbial population growth dynamics","authors":"Dina Mant, Tomer Orevi, Nadav Kashtan","doi":"10.1093/ismejo/wrae256","DOIUrl":"https://doi.org/10.1093/ismejo/wrae256","url":null,"abstract":"Microbial communities thrive in virtually every habitat on Earth and are essential to the function of diverse ecosystems. Most microbial habitats are not spatially continuous and well-mixed, but rather composed, at the microscale, of many isolated or semi-isolated local patches of different sizes, resulting in partitioning of microbial populations into discrete local populations. The impact of this spatial fragmentation on population dynamics is not well-understood. Here, we study how such variably sized micro-habitat patches affect the growth dynamics of clonal microbial populations and how dynamics in individual patches dictate those of the metapopulation. To investigate this, we developed the μ-SPLASH, an ecology-on-a-chip platform, enabling the culture of microbes in microscopic landscapes comprised of thousands of microdroplets, with a wide range of sizes. Using the μ-SPLASH, we cultured the model bacteria E. coli and based on time-lapse microscopy, analyzed the population dynamics within thousands of individual droplets. Our results reveal that growth curves substantially vary with droplet size. Although growth rates generally increase with drop size, reproductive success and the time to approach carrying capacity, display non-monotonic patterns. Combining μ-SPLASH experiments with computational modeling, we show that these patterns result from both stochastic and deterministic processes, and demonstrate the roles of initial population density, patchiness, and patch size distribution in dictating the local and metapopulation dynamics. This study reveals basic principles that elucidate the effects of habitat fragmentation and population partitioning on microbial population dynamics. These insights deepen our understanding of natural microbial communities and have significant implications for microbiome engineering.","PeriodicalId":516554,"journal":{"name":"The ISME Journal","volume":"32 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-12-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142874344","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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