Sarah J Tucker, Kelle C Freel, A Murat Eren, Michael S Rappé
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.
{"title":"Habitat-specificity in SAR11 is associated with a few genes under high selection","authors":"Sarah J Tucker, Kelle C Freel, A Murat Eren, Michael S Rappé","doi":"10.1093/ismejo/wraf216","DOIUrl":"https://doi.org/10.1093/ismejo/wraf216","url":null,"abstract":"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.","PeriodicalId":516554,"journal":{"name":"The ISME Journal","volume":"10 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-10-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145261600","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}
Bacterial locomotion is integral to acquiring resources and getting access to new niches. Swarming, a type of motility where flagellated bacteria cooperatively move together across a semi solid surface, is one example of how bacteria can colonize new territories. This collective behavior is temporally and spatially orchestrated, requiring task specialization of community members. In this study, we paired a swarming bacterium, Paenibacillus amylolyticus, with a non-swarmer, Stenotrophomonas maltophilia, to investigate the impact on fitness of each strain. In dual-species conditions, the community swarm became significantly thicker and improved the ability of S. maltophilia to range into new territories. Swarming enabled P. amylolyticus to cross barriers of antimicrobials, whereas the thicker, dual-species swarm did not empower S. maltophilia to cross. Comparative studies of population dynamics revealed that over time, monospecies swarms of P. amylolyticus entered a state unable to grow despite still showing reductase activity. However, in a dual-species swarm, S. maltophilia rescued P. amylolyticus from this state. This rescue is attributed to the pH stabilization that occurs in this two-species combination, where S. maltophilia alkalizes the environment, thereby providing a more favorable environment for P. amylolyticus.
{"title":"Co-cultivation rescues suicidal Paenibacillus amylolyticus swarms.","authors":"Dana Ronin,Mads Frederik Hansen,Mette Burmølle","doi":"10.1093/ismejo/wraf225","DOIUrl":"https://doi.org/10.1093/ismejo/wraf225","url":null,"abstract":"Bacterial locomotion is integral to acquiring resources and getting access to new niches. Swarming, a type of motility where flagellated bacteria cooperatively move together across a semi solid surface, is one example of how bacteria can colonize new territories. This collective behavior is temporally and spatially orchestrated, requiring task specialization of community members. In this study, we paired a swarming bacterium, Paenibacillus amylolyticus, with a non-swarmer, Stenotrophomonas maltophilia, to investigate the impact on fitness of each strain. In dual-species conditions, the community swarm became significantly thicker and improved the ability of S. maltophilia to range into new territories. Swarming enabled P. amylolyticus to cross barriers of antimicrobials, whereas the thicker, dual-species swarm did not empower S. maltophilia to cross. Comparative studies of population dynamics revealed that over time, monospecies swarms of P. amylolyticus entered a state unable to grow despite still showing reductase activity. However, in a dual-species swarm, S. maltophilia rescued P. amylolyticus from this state. This rescue is attributed to the pH stabilization that occurs in this two-species combination, where S. maltophilia alkalizes the environment, thereby providing a more favorable environment for P. amylolyticus.","PeriodicalId":516554,"journal":{"name":"The ISME Journal","volume":"64 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-10-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145247114","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}
Yihua Liu,Alyse K Kiesser,Agasteswar Vadlamani,Angela Kouris,Marc Strous
Alkaline soda lakes, characterized by high pH and high concentrations of sodium and dissolved carbonates, support diverse alkaliphilic microbial communities. Using stable isotope probing with 13C-bicarbonate, 15N-ammonium, 15N-nitrate, and 15N-urea, we measured assimilation rates for carbon and nitrogen by microbial mats of alkaline Goodenough Lake, Canada. Our results showed extremely high carbon fixation rates averaging 24 g C/m2/day, equalling or exceeding rates measured fifty years ago in African alkaline soda lakes. Urea consumption occurred both during the day and during the night, but assimilation mainly occurred during the day. Ammonium assimilation was stable between day and night. Apparently, cyanobacteria preferred urea as a nitrogen source, whereas heterotrophs preferred ammonium. Two different cyanobacteria dominated the microbial mats, Nodosilinea and Sodalinema. Using Orbitrap mass spectrometry, we only observed assimilation of 13C bicarbonate by Sodalinema, but not by Nodosilinea. The latter might focus on different carbon sources, such as urea. Strong negative correlation between their abundances in proteomes also supported niche partitioning between these two cyanobacteria.
碱性苏打湖的特点是pH值高,钠和溶解的碳酸盐浓度高,支持多种亲碱微生物群落。采用13c -碳酸氢盐、15n -铵、15n -硝酸盐和15n -尿素等稳定同位素探测,测定了加拿大古迪纳夫湖碱性微生物垫对碳和氮的同化速率。我们的研究结果显示了极高的碳固定率,平均为24 g C/m2/天,等于或超过了50年前在非洲碱性苏打湖中测量到的碳固定率。尿素消耗在白天和夜间都有发生,但同化主要发生在白天。铵态氮同化在白天和夜间都是稳定的。显然,蓝藻偏爱尿素作为氮源,而异养菌偏爱铵。两种不同的蓝藻占据了微生物席,Nodosilinea和Sodalinema。利用Orbitrap质谱法,我们只观察到Sodalinema对碳酸盐13C的同化作用,而Nodosilinea则没有。后者可能侧重于不同的碳源,如尿素。它们在蛋白质组中丰度之间的强负相关也支持这两种蓝藻之间的生态位分配。
{"title":"Exceptionally high carbon fixation and nitrogen assimilation rates in microbial mats of an alkaline soda lake.","authors":"Yihua Liu,Alyse K Kiesser,Agasteswar Vadlamani,Angela Kouris,Marc Strous","doi":"10.1093/ismejo/wraf226","DOIUrl":"https://doi.org/10.1093/ismejo/wraf226","url":null,"abstract":"Alkaline soda lakes, characterized by high pH and high concentrations of sodium and dissolved carbonates, support diverse alkaliphilic microbial communities. Using stable isotope probing with 13C-bicarbonate, 15N-ammonium, 15N-nitrate, and 15N-urea, we measured assimilation rates for carbon and nitrogen by microbial mats of alkaline Goodenough Lake, Canada. Our results showed extremely high carbon fixation rates averaging 24 g C/m2/day, equalling or exceeding rates measured fifty years ago in African alkaline soda lakes. Urea consumption occurred both during the day and during the night, but assimilation mainly occurred during the day. Ammonium assimilation was stable between day and night. Apparently, cyanobacteria preferred urea as a nitrogen source, whereas heterotrophs preferred ammonium. Two different cyanobacteria dominated the microbial mats, Nodosilinea and Sodalinema. Using Orbitrap mass spectrometry, we only observed assimilation of 13C bicarbonate by Sodalinema, but not by Nodosilinea. The latter might focus on different carbon sources, such as urea. Strong negative correlation between their abundances in proteomes also supported niche partitioning between these two cyanobacteria.","PeriodicalId":516554,"journal":{"name":"The ISME Journal","volume":"111 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-10-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145247026","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}
Clifton P Bueno de Mesquita,Matthew R Olm,Andrew Bissett,Noah Fierer
Global surveys of soil bacteria have identified several taxa that are nearly ubiquitous and often the most abundant members of soil bacterial communities. However, it remains unclear why these taxa are so abundant and prevalent across a wide range of soil types and environmental conditions. Here we use genome-resolved metagenomics to test the hypothesis that strain-level differences exist in these taxa that are not adequately captured with standard marker gene sequencing, and that distinct strains harbor unique traits that reflect adaptations to different soil environments. We analyzed data from 331 natural soils spanning Australia to assess strain differentiation in Bradyrhizobium, a dominant soil bacterial genus of ecological importance. We developed a workflow for strain-level bacterial analyses of complex soil metagenomes, combining genomes from pre-existing databases with new genomes generated via targeted assembly from metagenomes to detect 181 Bradyrhizobium strains across the soil collection. In addition to a high degree of phylogenetic variation, we observed substantial variation in pangenome content and inferred traits, highlighting the breadth of diversity within this widespread genus. Although members of the genus Bradyrhizobium were detected in >80% of samples, most individual strains were restricted in their distributions. The overall strain-level community composition of Bradyrhizobium varied significantly across geographic space and environmental gradients, and was particularly associated with differences in temperature, soil pH, and soil nitrate and metal concentrations. Our work provides a general framework for studying the strain-level ecology of soil bacteria and highlights the ecological and pangenomic diversity within this dominant soil bacterial genus.
{"title":"High strain-level diversity of Bradyrhizobium across Australian soils.","authors":"Clifton P Bueno de Mesquita,Matthew R Olm,Andrew Bissett,Noah Fierer","doi":"10.1093/ismejo/wraf222","DOIUrl":"https://doi.org/10.1093/ismejo/wraf222","url":null,"abstract":"Global surveys of soil bacteria have identified several taxa that are nearly ubiquitous and often the most abundant members of soil bacterial communities. However, it remains unclear why these taxa are so abundant and prevalent across a wide range of soil types and environmental conditions. Here we use genome-resolved metagenomics to test the hypothesis that strain-level differences exist in these taxa that are not adequately captured with standard marker gene sequencing, and that distinct strains harbor unique traits that reflect adaptations to different soil environments. We analyzed data from 331 natural soils spanning Australia to assess strain differentiation in Bradyrhizobium, a dominant soil bacterial genus of ecological importance. We developed a workflow for strain-level bacterial analyses of complex soil metagenomes, combining genomes from pre-existing databases with new genomes generated via targeted assembly from metagenomes to detect 181 Bradyrhizobium strains across the soil collection. In addition to a high degree of phylogenetic variation, we observed substantial variation in pangenome content and inferred traits, highlighting the breadth of diversity within this widespread genus. Although members of the genus Bradyrhizobium were detected in >80% of samples, most individual strains were restricted in their distributions. The overall strain-level community composition of Bradyrhizobium varied significantly across geographic space and environmental gradients, and was particularly associated with differences in temperature, soil pH, and soil nitrate and metal concentrations. Our work provides a general framework for studying the strain-level ecology of soil bacteria and highlights the ecological and pangenomic diversity within this dominant soil bacterial genus.","PeriodicalId":516554,"journal":{"name":"The ISME Journal","volume":"11 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-10-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145246610","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}
Bacterial communities exhibit various classes of interspecies interactions, ranging from synergistic to competitive. As these interaction classes play a crucial role in determining characteristics of bacterial communities, including species composition and community stability, understanding the mechanisms that shape them is important. Whereas several studies have suggested that synergistic interactions are rare, a study focused on single-carbon-source environments reported them to be relatively common. This discrepancy highlights the potential role of carbon source diversity in shaping interaction classes, although the quantitative relationship remains unclear. To elucidate this relationship, we examined 896 interspecies interactions among 28 synthetic bacterial pairs, isolated from various environments, under 32 conditions with varying levels of carbon source diversity. As a result, we frequently observed synergistic interactions in single-carbon-source environments, with the interactions shifting to competitive as the carbon source diversity increased. Further analyses suggested that this shift was driven by processes occurring in environments with an increased diversity of carbon sources, such as resource competition. Our findings provide new insights into how environmental factors, particularly carbon source diversity, shape interspecies interactions in bacterial communities.
{"title":"Carbon source diversity shapes bacterial interspecies interactions","authors":"Hiroki Ono, Saburo Tsuru, Chikara Furusawa","doi":"10.1093/ismejo/wraf224","DOIUrl":"https://doi.org/10.1093/ismejo/wraf224","url":null,"abstract":"Bacterial communities exhibit various classes of interspecies interactions, ranging from synergistic to competitive. As these interaction classes play a crucial role in determining characteristics of bacterial communities, including species composition and community stability, understanding the mechanisms that shape them is important. Whereas several studies have suggested that synergistic interactions are rare, a study focused on single-carbon-source environments reported them to be relatively common. This discrepancy highlights the potential role of carbon source diversity in shaping interaction classes, although the quantitative relationship remains unclear. To elucidate this relationship, we examined 896 interspecies interactions among 28 synthetic bacterial pairs, isolated from various environments, under 32 conditions with varying levels of carbon source diversity. As a result, we frequently observed synergistic interactions in single-carbon-source environments, with the interactions shifting to competitive as the carbon source diversity increased. Further analyses suggested that this shift was driven by processes occurring in environments with an increased diversity of carbon sources, such as resource competition. Our findings provide new insights into how environmental factors, particularly carbon source diversity, shape interspecies interactions in bacterial communities.","PeriodicalId":516554,"journal":{"name":"The ISME Journal","volume":"24 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-10-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145247045","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}
SAR11 bacteria are ubiquitous and abundant heterotrophs that are important mediators of marine biogeochemical cycles. Within the SAR11 clade smaller ecotypes inhabit different ecological niches. Using metagenomic read placement onto a phylogenetic tree of RNA polymerase (rpoB), we were able to determine the distribution of different ecotypes both geographically and by depth. Our method avoids biases from the absence of quality sequenced genomes for deep SAR11 ecotypes. Depth profiles that range from the surface to the bathypelagic were analyzed at 30 stations in 6 ocean basins. In the euphotic zone, changes in the dominant primary producer from eukaryotic algae to cyanobacteria, did not cause the abundance of SAR11 to shift between stations. However, specific SAR11 ecotypes did correlate with eukaryotic phytoplankton (1a.3 and 1a.4) or picocyanobacteria (1b.2, 1b.4, and IIaB). In the lower euphotic and mesopelagic zones, group IIb.x was overwhelmingly the dominant species but group 1c was also present, and we found several new deep sub-ecotypes of 1b. The shift between the surface SAR11 community, dominated by 1a and surface 1b sub-ecotypes, and the mesopelagic ecotype groups, corresponded to the maximum decrease in the light-dependent proteorhodopsin/rpoB ratio, indicating that many deep ecotypes did not possess proteorhodopsin. This ecotype switch repeatedly corresponded to the maximum in Low Light I Prochlorococcus, leading to the hypothesis that changes in light motivates the ecotype switch. Environmentally abiotic factors like light and temperature appear to be determining factors in the SAR11 ecotype distribution throughout the global oceans.
{"title":"SAR11 ecotypes across ocean basins change with depth due to changes in light and oxygen.","authors":"Matthew D Hays,Clara A Fuchsman","doi":"10.1093/ismejo/wraf221","DOIUrl":"https://doi.org/10.1093/ismejo/wraf221","url":null,"abstract":"SAR11 bacteria are ubiquitous and abundant heterotrophs that are important mediators of marine biogeochemical cycles. Within the SAR11 clade smaller ecotypes inhabit different ecological niches. Using metagenomic read placement onto a phylogenetic tree of RNA polymerase (rpoB), we were able to determine the distribution of different ecotypes both geographically and by depth. Our method avoids biases from the absence of quality sequenced genomes for deep SAR11 ecotypes. Depth profiles that range from the surface to the bathypelagic were analyzed at 30 stations in 6 ocean basins. In the euphotic zone, changes in the dominant primary producer from eukaryotic algae to cyanobacteria, did not cause the abundance of SAR11 to shift between stations. However, specific SAR11 ecotypes did correlate with eukaryotic phytoplankton (1a.3 and 1a.4) or picocyanobacteria (1b.2, 1b.4, and IIaB). In the lower euphotic and mesopelagic zones, group IIb.x was overwhelmingly the dominant species but group 1c was also present, and we found several new deep sub-ecotypes of 1b. The shift between the surface SAR11 community, dominated by 1a and surface 1b sub-ecotypes, and the mesopelagic ecotype groups, corresponded to the maximum decrease in the light-dependent proteorhodopsin/rpoB ratio, indicating that many deep ecotypes did not possess proteorhodopsin. This ecotype switch repeatedly corresponded to the maximum in Low Light I Prochlorococcus, leading to the hypothesis that changes in light motivates the ecotype switch. Environmentally abiotic factors like light and temperature appear to be determining factors in the SAR11 ecotype distribution throughout the global oceans.","PeriodicalId":516554,"journal":{"name":"The ISME Journal","volume":"25 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-10-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145246609","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}
Lytic proteins, essential for viral life cycles, mediate cell lysis, driving nutrient and gene flow in ecosystems. Despite advances in understanding viral lysis mechanisms, the lytic proteins of prokaryotic viruses remain poorly understood at the macroevolutionary scale. Here, we constructed the Prokaryotic DNA Virus Lytic Protein Dataset, revealing the diversity, distribution patterns, and evolutionary drivers of lytic proteins across viral genomes. Our results demonstrate sequence and structural variation, suggesting that the composition of the lysis system is closely linked to viral genome size, host cell wall structure, and lifestyle, reflecting ecological adaptation. We observed that viral lytic proteins exhibit extensive sequence variation but retain structural conservation, suggesting a stronger selective pressure on structure that may be driven by the need to adapt and conform with specific cell envelope architectures. Phylogenetic analyses identified a significant co-evolutionary signal among lytic proteins, alongside extensive horizontal gene transfer of endolysin and holin encoding genes between bacteriophages and bacteria. These analyses also support that viral lytic proteins likely originated from bacterial sources, with different functional types having multiple independent origins. Moreover, comparative analysis of DNA and RNA virus lytic proteins demonstrates their diversity and differences across viral lineages. Revealing vast unexplored lytic proteins diversity, this study highlights their biotechnological potential against multidrug-resistant pathogens.
{"title":"Diversity and Evolution of Prokaryotic Viral Lytic Proteins.","authors":"Ting Yang,Mujie Zhang,Yi Yi,Yecheng Wang,Zhiwei Wang,Rui Zhang,Xiang Xiao,Huahua Jian","doi":"10.1093/ismejo/wraf200","DOIUrl":"https://doi.org/10.1093/ismejo/wraf200","url":null,"abstract":"Lytic proteins, essential for viral life cycles, mediate cell lysis, driving nutrient and gene flow in ecosystems. Despite advances in understanding viral lysis mechanisms, the lytic proteins of prokaryotic viruses remain poorly understood at the macroevolutionary scale. Here, we constructed the Prokaryotic DNA Virus Lytic Protein Dataset, revealing the diversity, distribution patterns, and evolutionary drivers of lytic proteins across viral genomes. Our results demonstrate sequence and structural variation, suggesting that the composition of the lysis system is closely linked to viral genome size, host cell wall structure, and lifestyle, reflecting ecological adaptation. We observed that viral lytic proteins exhibit extensive sequence variation but retain structural conservation, suggesting a stronger selective pressure on structure that may be driven by the need to adapt and conform with specific cell envelope architectures. Phylogenetic analyses identified a significant co-evolutionary signal among lytic proteins, alongside extensive horizontal gene transfer of endolysin and holin encoding genes between bacteriophages and bacteria. These analyses also support that viral lytic proteins likely originated from bacterial sources, with different functional types having multiple independent origins. Moreover, comparative analysis of DNA and RNA virus lytic proteins demonstrates their diversity and differences across viral lineages. Revealing vast unexplored lytic proteins diversity, this study highlights their biotechnological potential against multidrug-resistant pathogens.","PeriodicalId":516554,"journal":{"name":"The ISME Journal","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-10-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145246825","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}
Shan Li, Jiajia Liu, Lei Su, Jingwen Qiu, Lianbing Lin, Ákos T Kovács, Yicen Lin
Polyethylene, one of the most widely used synthetic polymers, presents significant environmental challenges due to its resistance to biodegradation. Its surface offers a unique ecological niche for microbial colonization and serves as a primary habitat for degrading microorganisms. Despite the pivotal role microbial communities play in plastic degradation, there has been limited research on constructing stable, interacting microbial consortia. In this study, we explored the potential of evolving bacterial biofilm communities to enhance polyethylene degradation. Through long-term experimental evolution, six microbial populations underwent 40 selection cycles using polyethylene as their sole carbon source. The resulting evolved communities formed robust, multi-species biofilms with enhanced degradation capabilities, outperforming their ancestral populations in biofilm production. Stutzerimonas stutzeri emerged as the dominant species, orchestrating a synergistic interaction with two other isolates through metabolic division of labor. (Meta)-transcriptomics analysis revealed that Stutzerimonas primarily contributed to the expression of enzymes involved in microbe-mediated degradation of polyethylene, whereas the other community members were responsible for secreting extracellular polysaccharides, improving biofilm formation. This study highlights the potential of experimentally evolved microbial consortia to synergistically accelerate plastic biodegradation, offering promising strategies for environmental bioremediation.
{"title":"Synergistic biodegradation of polyethylene by experimentally evolved bacterial biofilms","authors":"Shan Li, Jiajia Liu, Lei Su, Jingwen Qiu, Lianbing Lin, Ákos T Kovács, Yicen Lin","doi":"10.1093/ismejo/wraf223","DOIUrl":"https://doi.org/10.1093/ismejo/wraf223","url":null,"abstract":"Polyethylene, one of the most widely used synthetic polymers, presents significant environmental challenges due to its resistance to biodegradation. Its surface offers a unique ecological niche for microbial colonization and serves as a primary habitat for degrading microorganisms. Despite the pivotal role microbial communities play in plastic degradation, there has been limited research on constructing stable, interacting microbial consortia. In this study, we explored the potential of evolving bacterial biofilm communities to enhance polyethylene degradation. Through long-term experimental evolution, six microbial populations underwent 40 selection cycles using polyethylene as their sole carbon source. The resulting evolved communities formed robust, multi-species biofilms with enhanced degradation capabilities, outperforming their ancestral populations in biofilm production. Stutzerimonas stutzeri emerged as the dominant species, orchestrating a synergistic interaction with two other isolates through metabolic division of labor. (Meta)-transcriptomics analysis revealed that Stutzerimonas primarily contributed to the expression of enzymes involved in microbe-mediated degradation of polyethylene, whereas the other community members were responsible for secreting extracellular polysaccharides, improving biofilm formation. This study highlights the potential of experimentally evolved microbial consortia to synergistically accelerate plastic biodegradation, offering promising strategies for environmental bioremediation.","PeriodicalId":516554,"journal":{"name":"The ISME Journal","volume":"82 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-10-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145247046","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}
Joanna A Lepper,H B Beryl Rappaport,Angela M Oliverio
Although microbial eukaryotes comprise the majority of eukaryotic phylogenetic diversity and inhabit nearly all ecosystems globally, most research focuses on only a few species of human parasites. Here, we quantify the extent of research on known microbial eukaryotic species. Nearly half of the mentions of protist species on publications in PubMed referenced only 10 species included in the Protist Ribosomal Reference (PR2) Database. Likewise, although most samples in the PR2 database are free-living protists from aquatic environments, 12 species of human parasites comprise 47% of the literature. Research efforts that focus on only a handful of eukaryotic lineages severely limit our understanding of the fundamental biology of eukaryotic cells. We highlight recent efforts to characterize novel eukaryotic lineages that have resulted in a new understanding of the rules of life and identify key lineages that are notably absent or limited in the literature, despite their abundance and significance across global ecosystems.
{"title":"Half of microbial eukaryote literature focuses on only twelve human parasites.","authors":"Joanna A Lepper,H B Beryl Rappaport,Angela M Oliverio","doi":"10.1093/ismejo/wraf219","DOIUrl":"https://doi.org/10.1093/ismejo/wraf219","url":null,"abstract":"Although microbial eukaryotes comprise the majority of eukaryotic phylogenetic diversity and inhabit nearly all ecosystems globally, most research focuses on only a few species of human parasites. Here, we quantify the extent of research on known microbial eukaryotic species. Nearly half of the mentions of protist species on publications in PubMed referenced only 10 species included in the Protist Ribosomal Reference (PR2) Database. Likewise, although most samples in the PR2 database are free-living protists from aquatic environments, 12 species of human parasites comprise 47% of the literature. Research efforts that focus on only a handful of eukaryotic lineages severely limit our understanding of the fundamental biology of eukaryotic cells. We highlight recent efforts to characterize novel eukaryotic lineages that have resulted in a new understanding of the rules of life and identify key lineages that are notably absent or limited in the literature, despite their abundance and significance across global ecosystems.","PeriodicalId":516554,"journal":{"name":"The ISME Journal","volume":"348 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-10-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145235980","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}
Quorum sensing (QS) is a chemical communication process that connects microbial members in various microbial systems. Bacterial communication networks mediated by QS play important roles in the regulation of intestinal microecological balance as well as nutrition and metabolism of the host. However, how human gut microbes utilize QS signals to communicate with one another remains largely unknown. In this study, we first examined the prevalence and abundance of genes encoding QS signal synthases in 3329 species representatives clustered from 289232 prokaryotic genomes in the Unified Human Gastrointestinal Genome collection. Our results show autoinducer-2 (AI-2) is the most prevalent QS signal within the human gut microbiota, with the synthase gene luxS being found in 2039 species mainly distributed within Firmicutes, Actinobacteriota, Bacteroidota, and Proteobacteria. Furthermore, 299 species carry genes encoding one or more types of AI-2 receptors (LuxP-, LsrB-, dCache_1-, and GAPES1-type). The dCache_1- and GAPES1-type receptors can function as methyl-accepting chemotaxis proteins, histidine kinases, c-di-GMP synthases and/or c-di-GMP-specific phosphodiesterases, serine phosphatases, and serine/threonine kinases, suggesting the diversity of AI-2-mediated interspecies communication modes among human gut microbiota. Metatranscriptomic analysis showed that a number of AI-2 synthase- and receptor-encoding genes can be expressed in the human gut in healthy and/or unhealthy states. The communication network analysis suggests that AI-2-mediated interactions widely occur among members of Firmicutes, Proteobacteria, Actinobacteriota, Campylobacterota, and Spirochaetota. Overall, this study deepens understanding of QS-mediated communication network among human gut microbiota, and provides guidance for engineering gut microbiota and constructing new synthetic microbial consortia based on complex microbial interactions.
{"title":"Autoinducer-2-mediated communication network within human gut microbiota","authors":"Qingying Fan, Hengxi Sun, Xueyuan Lin, Wenguang Yang, Xihui Shen, Lei Zhang","doi":"10.1093/ismejo/wraf204","DOIUrl":"https://doi.org/10.1093/ismejo/wraf204","url":null,"abstract":"Quorum sensing (QS) is a chemical communication process that connects microbial members in various microbial systems. Bacterial communication networks mediated by QS play important roles in the regulation of intestinal microecological balance as well as nutrition and metabolism of the host. However, how human gut microbes utilize QS signals to communicate with one another remains largely unknown. In this study, we first examined the prevalence and abundance of genes encoding QS signal synthases in 3329 species representatives clustered from 289232 prokaryotic genomes in the Unified Human Gastrointestinal Genome collection. Our results show autoinducer-2 (AI-2) is the most prevalent QS signal within the human gut microbiota, with the synthase gene luxS being found in 2039 species mainly distributed within Firmicutes, Actinobacteriota, Bacteroidota, and Proteobacteria. Furthermore, 299 species carry genes encoding one or more types of AI-2 receptors (LuxP-, LsrB-, dCache_1-, and GAPES1-type). The dCache_1- and GAPES1-type receptors can function as methyl-accepting chemotaxis proteins, histidine kinases, c-di-GMP synthases and/or c-di-GMP-specific phosphodiesterases, serine phosphatases, and serine/threonine kinases, suggesting the diversity of AI-2-mediated interspecies communication modes among human gut microbiota. Metatranscriptomic analysis showed that a number of AI-2 synthase- and receptor-encoding genes can be expressed in the human gut in healthy and/or unhealthy states. The communication network analysis suggests that AI-2-mediated interactions widely occur among members of Firmicutes, Proteobacteria, Actinobacteriota, Campylobacterota, and Spirochaetota. Overall, this study deepens understanding of QS-mediated communication network among human gut microbiota, and provides guidance for engineering gut microbiota and constructing new synthetic microbial consortia based on complex microbial interactions.","PeriodicalId":516554,"journal":{"name":"The ISME Journal","volume":"9 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-10-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145241900","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}