Yanning Liu, Rengang Luo, Shuai Bai, Bruno Lemaitre, Hongyu Zhang, Xiaoxue Li
Host-gut microbiota interactions are more complex than good or bad. Both gut symbiotic bacteria and pathobionts can provide essential functions to their host in one scenario and yet be detrimental to host health in another. So, these gut-dwelling bacteria must be tightly controlled to avoid harmful effects on the host. However, how pathobionts and other symbiotic bacteria coordinate to establish a host immune defense system remains unclear. Here, using a Tephritidae fruit fly Bactrocera dorsalis, we report that both pathobionts and other gut symbiotic bacteria release tyramine, which is recognized by the host insects. These tyramines induce the formation of insect-conserved Malpighian tubules-gut countercurrent flow upon bacterial infection, which requires tyramine receptors and aquaporins. At the same time, pathobionts but not gut symbiotic bacteria induce the generation of reactive oxygen species, which are preserved by the countercurrent flow, promoting bacteria elimination through increasing gut peristalsis. More importantly, our results show that the Malpighian tubules-gut countercurrent flow maintains proper microbiota composition. Our work suggests a model where pathobiont-induced reactive oxygen species are preserved by Malpighian tubules-gut countercurrent flow involving both pathobionts and symbiotic bacteria. Furthermore, our work provides a Malpighian tubules-gut interaction that ensures efficient maintenance of the gut microbiota.
{"title":"Pathobiont and symbiont contribute to microbiota homeostasis through Malpighian tubules-gut countercurrent flow in Bactrocera dorsalis","authors":"Yanning Liu, Rengang Luo, Shuai Bai, Bruno Lemaitre, Hongyu Zhang, Xiaoxue Li","doi":"10.1093/ismejo/wrae221","DOIUrl":"https://doi.org/10.1093/ismejo/wrae221","url":null,"abstract":"Host-gut microbiota interactions are more complex than good or bad. Both gut symbiotic bacteria and pathobionts can provide essential functions to their host in one scenario and yet be detrimental to host health in another. So, these gut-dwelling bacteria must be tightly controlled to avoid harmful effects on the host. However, how pathobionts and other symbiotic bacteria coordinate to establish a host immune defense system remains unclear. Here, using a Tephritidae fruit fly Bactrocera dorsalis, we report that both pathobionts and other gut symbiotic bacteria release tyramine, which is recognized by the host insects. These tyramines induce the formation of insect-conserved Malpighian tubules-gut countercurrent flow upon bacterial infection, which requires tyramine receptors and aquaporins. At the same time, pathobionts but not gut symbiotic bacteria induce the generation of reactive oxygen species, which are preserved by the countercurrent flow, promoting bacteria elimination through increasing gut peristalsis. More importantly, our results show that the Malpighian tubules-gut countercurrent flow maintains proper microbiota composition. Our work suggests a model where pathobiont-induced reactive oxygen species are preserved by Malpighian tubules-gut countercurrent flow involving both pathobionts and symbiotic bacteria. Furthermore, our work provides a Malpighian tubules-gut interaction that ensures efficient maintenance of the gut microbiota.","PeriodicalId":516554,"journal":{"name":"The ISME Journal","volume":"156 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-11-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142601236","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}
Nestor Arandia-Gorostidi, Alexander L Jaffe, Alma E Parada, Bennett J Kapili, Karen L Casciotti, Rebecca S R Salcedo, Chloé M J Baumas, Anne E Dekas
Urea is hypothesized to be an important source of nitrogen and chemical energy to microorganisms in the deep sea; however, direct evidence for urea use below the epipelagic ocean is lacking. Here, we explore urea utilization from 50 to 4000 meters depth in the northeastern Pacific Ocean using metagenomics, nitrification rates, and single-cell stable-isotope-uptake measurements with nanoscale secondary ion mass spectrometry. We find that on average 25% of deep-sea cells assimilated urea-derived N (60% of detectably active cells), and that cell-specific nitrogen-incorporation rates from urea were higher than that from ammonium. Both urea concentrations and assimilation rates relative to ammonium generally increased below the euphotic zone. We detected ammonia- and urea-based nitrification at all depths at one of two sites analyzed, demonstrating their potential to support chemoautotrophy in the mesopelagic and bathypelagic regions. Using newly generated metagenomes we find that the ureC gene, encoding the catalytic subunit of urease, is found within 39% of deep-sea cells in this region, including the Nitrososphaeria (syn., Thaumarchaeota; likely for nitrification) as well as members of thirteen other phyla such as Proteobacteria, Verrucomicrobia, Plantomycetota, Nitrospinota, and Chloroflexota (likely for assimilation). Analysis of public metagenomes estimated ureC within 10–46% of deep-sea cells around the world, with higher prevalence below the photic zone, suggesting urea is widely available to the deep-sea microbiome globally. Our results demonstrate that urea is a nitrogen source to abundant and diverse microorganisms in the dark ocean, as well as a significant contributor to deep-sea nitrification and therefore fuel for chemoautotrophy.
{"title":"Urea assimilation and oxidation support activity of phylogenetically diverse microbial communities of the dark ocean","authors":"Nestor Arandia-Gorostidi, Alexander L Jaffe, Alma E Parada, Bennett J Kapili, Karen L Casciotti, Rebecca S R Salcedo, Chloé M J Baumas, Anne E Dekas","doi":"10.1093/ismejo/wrae230","DOIUrl":"https://doi.org/10.1093/ismejo/wrae230","url":null,"abstract":"Urea is hypothesized to be an important source of nitrogen and chemical energy to microorganisms in the deep sea; however, direct evidence for urea use below the epipelagic ocean is lacking. Here, we explore urea utilization from 50 to 4000 meters depth in the northeastern Pacific Ocean using metagenomics, nitrification rates, and single-cell stable-isotope-uptake measurements with nanoscale secondary ion mass spectrometry. We find that on average 25% of deep-sea cells assimilated urea-derived N (60% of detectably active cells), and that cell-specific nitrogen-incorporation rates from urea were higher than that from ammonium. Both urea concentrations and assimilation rates relative to ammonium generally increased below the euphotic zone. We detected ammonia- and urea-based nitrification at all depths at one of two sites analyzed, demonstrating their potential to support chemoautotrophy in the mesopelagic and bathypelagic regions. Using newly generated metagenomes we find that the ureC gene, encoding the catalytic subunit of urease, is found within 39% of deep-sea cells in this region, including the Nitrososphaeria (syn., Thaumarchaeota; likely for nitrification) as well as members of thirteen other phyla such as Proteobacteria, Verrucomicrobia, Plantomycetota, Nitrospinota, and Chloroflexota (likely for assimilation). Analysis of public metagenomes estimated ureC within 10–46% of deep-sea cells around the world, with higher prevalence below the photic zone, suggesting urea is widely available to the deep-sea microbiome globally. Our results demonstrate that urea is a nitrogen source to abundant and diverse microorganisms in the dark ocean, as well as a significant contributor to deep-sea nitrification and therefore fuel for chemoautotrophy.","PeriodicalId":516554,"journal":{"name":"The ISME Journal","volume":"78 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-11-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142599705","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}
Linear waste management systems are unsustainable and contribute to environmental degradation, economic inequity, and health disparities. Among the array of environmental challenges stemming from anthropogenic impacts, the management of human excrement (human feces and urine) stands as a significant concern. Over two billion people do not have access to adequate sanitation, signifying a global public health crisis. Composting is the microbial biotechnology aimed at cycling organic waste, including human excrement, for improved public health, agricultural productivity and safety, and environmental sustainability. Applications of modern microbiome -omics and related technologies have the capacity to support continued advances in composting science and praxis. In this article, we review literature focused on applications of microbiome technologies to study composting systems and reactions. The studies we survey generally fall into the categories of animal manure composting, biosolids composting, and human excrement composting. We review experiments utilizing microbiome technologies to investigate strategies for enhancing pathogen suppression and accelerating the biodegradation of organic matter. Additionally, we explore studies focused on the bioengineering potential of microbes as inoculants to facilitate degradation of toxins such as pharmaceuticals or per- and polyfluoroalkyl substances. The findings from these studies underscore the importance of advancing our understanding of composting processes through the integration of emerging microbiome -omics technologies. We conclude that work to-date has demonstrated exciting basic and applied science potential from studying compost microbiomes, with promising implications for enhancing global environmental sustainability and public health.
{"title":"Microbiome science of human excrement composting","authors":"Jeff Meilander, J Gregory Caporaso","doi":"10.1093/ismejo/wrae228","DOIUrl":"https://doi.org/10.1093/ismejo/wrae228","url":null,"abstract":"Linear waste management systems are unsustainable and contribute to environmental degradation, economic inequity, and health disparities. Among the array of environmental challenges stemming from anthropogenic impacts, the management of human excrement (human feces and urine) stands as a significant concern. Over two billion people do not have access to adequate sanitation, signifying a global public health crisis. Composting is the microbial biotechnology aimed at cycling organic waste, including human excrement, for improved public health, agricultural productivity and safety, and environmental sustainability. Applications of modern microbiome -omics and related technologies have the capacity to support continued advances in composting science and praxis. In this article, we review literature focused on applications of microbiome technologies to study composting systems and reactions. The studies we survey generally fall into the categories of animal manure composting, biosolids composting, and human excrement composting. We review experiments utilizing microbiome technologies to investigate strategies for enhancing pathogen suppression and accelerating the biodegradation of organic matter. Additionally, we explore studies focused on the bioengineering potential of microbes as inoculants to facilitate degradation of toxins such as pharmaceuticals or per- and polyfluoroalkyl substances. The findings from these studies underscore the importance of advancing our understanding of composting processes through the integration of emerging microbiome -omics technologies. We conclude that work to-date has demonstrated exciting basic and applied science potential from studying compost microbiomes, with promising implications for enhancing global environmental sustainability and public health.","PeriodicalId":516554,"journal":{"name":"The ISME Journal","volume":"47 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-11-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142597655","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}
Shengwei Liu, Eleonora Silvano, Mingyu Li, Michaela Mausz, Branko Rihtman, Richard Guillonneau, Otto Geiger, David J Scanlan, Yin Chen
Our comprehension of membrane function has predominantly advanced through research on glycerophospholipids, also known as phosphoglycerides, which are glycerol phosphate-based lipids found across all three domains of life. However, in bacteria, a perplexing group of lipids distinct from glycerol phosphate-based ones also exists. These are amino acid-containing lipids that form an amide bond between an amino acid and a fatty acid. Subsequently, a second fatty acid becomes linked, often via the 3-hydroxy group on the first fatty acid. These amide-linked aminolipids have, as of now, been exclusively identified in bacteria. Several hydrophilic head groups have been discovered in these aminolipids including ornithine, glutamine, glycine, lysine, and more recently, a sulfur-containing non-proteinogenic amino acid cysteinolic acid. Here, we aim to review current advances in the genetics, biochemistry and function of these aminolipids as well as giving an ecological perspective. We provide evidence for their potential significance in the ecophysiology of all major microbiomes i.e. gut, soil and aquatic as well as highlighting their important roles in influencing biological interactions.
{"title":"Aminolipids in bacterial membranes and the natural environment","authors":"Shengwei Liu, Eleonora Silvano, Mingyu Li, Michaela Mausz, Branko Rihtman, Richard Guillonneau, Otto Geiger, David J Scanlan, Yin Chen","doi":"10.1093/ismejo/wrae229","DOIUrl":"https://doi.org/10.1093/ismejo/wrae229","url":null,"abstract":"Our comprehension of membrane function has predominantly advanced through research on glycerophospholipids, also known as phosphoglycerides, which are glycerol phosphate-based lipids found across all three domains of life. However, in bacteria, a perplexing group of lipids distinct from glycerol phosphate-based ones also exists. These are amino acid-containing lipids that form an amide bond between an amino acid and a fatty acid. Subsequently, a second fatty acid becomes linked, often via the 3-hydroxy group on the first fatty acid. These amide-linked aminolipids have, as of now, been exclusively identified in bacteria. Several hydrophilic head groups have been discovered in these aminolipids including ornithine, glutamine, glycine, lysine, and more recently, a sulfur-containing non-proteinogenic amino acid cysteinolic acid. Here, we aim to review current advances in the genetics, biochemistry and function of these aminolipids as well as giving an ecological perspective. We provide evidence for their potential significance in the ecophysiology of all major microbiomes i.e. gut, soil and aquatic as well as highlighting their important roles in influencing biological interactions.","PeriodicalId":516554,"journal":{"name":"The ISME Journal","volume":"35 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-11-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142597653","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}
Oscar Ramfelt, Kelle C Freel, Sarah J Tucker, Olivia D Nigro, Michael S Rappé
SAR86 is one of the most abundant groups of bacteria in the global surface ocean. However, since its discovery over 30 years ago, it has remained recalcitrant to isolation and many details regarding this group are still unknown. Here we report the cellular characteristics from the first SAR86 isolate brought into culture, Magnimaribacter mokuoloeensis strain HIMB1674, and use its closed genome in concert with over 700 environmental genomes to assess the phylogenomic and functional characteristics of this order-level lineage of marine Gammaproteobacteria. The SAR86 order Magnimaribacterales invest significant genomic resources into the capacity for $beta$-oxidation, which is present in most genomes in high gene copy numbers. This cyclical set of reactions appears to be fed by components of cell membranes that include lipids such as phosphatidylcholine, phosphatidylethanolamine, glycolipids, and sulfolipids. In addition to the widespread capacity to degrade the side chain of steroidal compounds via $beta$-oxidation, several SAR86 sublineages also appear able to fully degrade the steroid polycyclic ring structure as well as other aromatic, polycyclic, and heterocyclic molecules. Read recruitment from publicly available metagenomes reveals that the Magnimaribacterales compose up to 6% of the global surface ocean microbial community. Only a subset of genera drive these high relative abundances, with some more globally dominant and others restricted to specific oceanic regions. This study provides an unprecedented foundation through which to understand this highly abundant yet poorly understood lineage of marine bacteria, and charts a path to bring more representatives of this order into laboratory culture.
{"title":"Isolate-anchored comparisons reveal evolutionary and functional differentiation across SAR86 marine bacteria","authors":"Oscar Ramfelt, Kelle C Freel, Sarah J Tucker, Olivia D Nigro, Michael S Rappé","doi":"10.1093/ismejo/wrae227","DOIUrl":"https://doi.org/10.1093/ismejo/wrae227","url":null,"abstract":"SAR86 is one of the most abundant groups of bacteria in the global surface ocean. However, since its discovery over 30 years ago, it has remained recalcitrant to isolation and many details regarding this group are still unknown. Here we report the cellular characteristics from the first SAR86 isolate brought into culture, Magnimaribacter mokuoloeensis strain HIMB1674, and use its closed genome in concert with over 700 environmental genomes to assess the phylogenomic and functional characteristics of this order-level lineage of marine Gammaproteobacteria. The SAR86 order Magnimaribacterales invest significant genomic resources into the capacity for $beta$-oxidation, which is present in most genomes in high gene copy numbers. This cyclical set of reactions appears to be fed by components of cell membranes that include lipids such as phosphatidylcholine, phosphatidylethanolamine, glycolipids, and sulfolipids. In addition to the widespread capacity to degrade the side chain of steroidal compounds via $beta$-oxidation, several SAR86 sublineages also appear able to fully degrade the steroid polycyclic ring structure as well as other aromatic, polycyclic, and heterocyclic molecules. Read recruitment from publicly available metagenomes reveals that the Magnimaribacterales compose up to 6% of the global surface ocean microbial community. Only a subset of genera drive these high relative abundances, with some more globally dominant and others restricted to specific oceanic regions. This study provides an unprecedented foundation through which to understand this highly abundant yet poorly understood lineage of marine bacteria, and charts a path to bring more representatives of this order into laboratory culture.","PeriodicalId":516554,"journal":{"name":"The ISME Journal","volume":"38 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-11-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142597654","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}
Shicong Du, Xinzhao Tong, Marcus H Y Leung, Richard J Betts, Anthony C Woo, Philippe Bastien, Namita Misra, Luc Aguilar, Cécile Clavaud, Patrick K H Lee
Exposure to polycyclic aromatic hydrocarbons (PAHs) in polluted air influences the composition of the skin microbiome, which in turn is associated with altered skin phenotypes. However, the interactions between PAH exposure and viromes are unclear. This study aims to elucidate how PAH exposure affects the composition and function of skin viruses, their role in shaping the metabolism of bacterial hosts, and the subsequent effects on skin phenotype. We analyzed metagenomes from cheek skin swabs collected from 124 Chinese women in our previous study and found that the viruses associated with the two microbiome cutotypes had distinct diversities, compositions, functions, and lifestyles following PAH exposure. Moreover, exposure to high concentrations of PAHs substantially increased interactions between viruses and certain biodegrading bacteria. Under high-PAH exposure, the viruses were enriched in xenobiotic degradation functions, and there was evidence suggesting that the insertion of bacteriophage-encoded auxiliary metabolic genes into hosts aids biodegradation. Under low-PAH exposure conditions, the interactions followed the “Piggyback-the-Winner” model, with Cutibacterium acnes being “winners,” whereas under high-PAH exposure, they followed the “Piggyback-the-Persistent” model, with biodegradation bacteria being “persistent.” These findings highlight the impact of air pollutants on skin bacteria and viruses, their interactions, and their modulation of skin health. Understanding these intricate relationships could provide insights for developing targeted strategies to maintain skin health in polluted environments, emphasizing the importance of mitigating pollutant exposure and harnessing the potential of viruses to help counteract the adverse effects.
{"title":"Chronic exposure to polycyclic aromatic hydrocarbons alters skin virome composition and virus–host interactions","authors":"Shicong Du, Xinzhao Tong, Marcus H Y Leung, Richard J Betts, Anthony C Woo, Philippe Bastien, Namita Misra, Luc Aguilar, Cécile Clavaud, Patrick K H Lee","doi":"10.1093/ismejo/wrae218","DOIUrl":"https://doi.org/10.1093/ismejo/wrae218","url":null,"abstract":"Exposure to polycyclic aromatic hydrocarbons (PAHs) in polluted air influences the composition of the skin microbiome, which in turn is associated with altered skin phenotypes. However, the interactions between PAH exposure and viromes are unclear. This study aims to elucidate how PAH exposure affects the composition and function of skin viruses, their role in shaping the metabolism of bacterial hosts, and the subsequent effects on skin phenotype. We analyzed metagenomes from cheek skin swabs collected from 124 Chinese women in our previous study and found that the viruses associated with the two microbiome cutotypes had distinct diversities, compositions, functions, and lifestyles following PAH exposure. Moreover, exposure to high concentrations of PAHs substantially increased interactions between viruses and certain biodegrading bacteria. Under high-PAH exposure, the viruses were enriched in xenobiotic degradation functions, and there was evidence suggesting that the insertion of bacteriophage-encoded auxiliary metabolic genes into hosts aids biodegradation. Under low-PAH exposure conditions, the interactions followed the “Piggyback-the-Winner” model, with Cutibacterium acnes being “winners,” whereas under high-PAH exposure, they followed the “Piggyback-the-Persistent” model, with biodegradation bacteria being “persistent.” These findings highlight the impact of air pollutants on skin bacteria and viruses, their interactions, and their modulation of skin health. Understanding these intricate relationships could provide insights for developing targeted strategies to maintain skin health in polluted environments, emphasizing the importance of mitigating pollutant exposure and harnessing the potential of viruses to help counteract the adverse effects.","PeriodicalId":516554,"journal":{"name":"The ISME Journal","volume":"50 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-10-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142490401","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}
Marine viruses are key players of ocean biogeochemistry, profoundly influencing microbial community ecology and evolution. Despite their importance, few studies have explored continuous inter-seasonal viral metagenomic time-series in marine environments. Viral dynamics are complex, influenced by multiple factors such as host population dynamics and environmental conditions. To disentangle the complexity of viral communities, we developed an unsupervised machine learning framework to classify viral contigs into "chronotypes" based on temporal abundance patterns. Analysing an inter-seasonal monthly time-series of surface viral metagenomes from the Western English Channel, we identified chronotypes and compared their functional and evolutionary profiles. Results revealed a consistent annual cycle with steep compositional changes from winter to summer and steadier transitions from summer to winter. Seasonal chronotypes were enriched in potential auxiliary metabolic genes of the ferrochelatases and 2OG-Fe(II) oxygenase orthologous groups compared to non-seasonal types. Chronotypes clustered into four groups based on their correlation profiles with environmental parameters, primarily driven by temperature and nutrients. Viral contigs exhibited a rapid turnover of polymorphisms, akin to Red Queen dynamics. However, within seasonal chronotypes, some sequences exhibited annual polymorphism recurrence, suggesting that a fraction of the seasonal viral populations evolve more slowly. Classification into chronotypes revealed viral genomic signatures linked to temporal patterns, likely reflecting metabolic adaptations to environmental fluctuations and host dynamics. This novel framework enables the identification of long-term trends in viral composition, environmental influences on genomic structure, and potential viral interactions.
{"title":"Metagenomic time-series reveals a western English Channel viral community dominated by members with strong seasonal signals","authors":"Luis M Bolaños, Michelle Michelsen, Ben Temperton","doi":"10.1093/ismejo/wrae216","DOIUrl":"https://doi.org/10.1093/ismejo/wrae216","url":null,"abstract":"Marine viruses are key players of ocean biogeochemistry, profoundly influencing microbial community ecology and evolution. Despite their importance, few studies have explored continuous inter-seasonal viral metagenomic time-series in marine environments. Viral dynamics are complex, influenced by multiple factors such as host population dynamics and environmental conditions. To disentangle the complexity of viral communities, we developed an unsupervised machine learning framework to classify viral contigs into \"chronotypes\" based on temporal abundance patterns. Analysing an inter-seasonal monthly time-series of surface viral metagenomes from the Western English Channel, we identified chronotypes and compared their functional and evolutionary profiles. Results revealed a consistent annual cycle with steep compositional changes from winter to summer and steadier transitions from summer to winter. Seasonal chronotypes were enriched in potential auxiliary metabolic genes of the ferrochelatases and 2OG-Fe(II) oxygenase orthologous groups compared to non-seasonal types. Chronotypes clustered into four groups based on their correlation profiles with environmental parameters, primarily driven by temperature and nutrients. Viral contigs exhibited a rapid turnover of polymorphisms, akin to Red Queen dynamics. However, within seasonal chronotypes, some sequences exhibited annual polymorphism recurrence, suggesting that a fraction of the seasonal viral populations evolve more slowly. Classification into chronotypes revealed viral genomic signatures linked to temporal patterns, likely reflecting metabolic adaptations to environmental fluctuations and host dynamics. This novel framework enables the identification of long-term trends in viral composition, environmental influences on genomic structure, and potential viral interactions.","PeriodicalId":516554,"journal":{"name":"The ISME Journal","volume":"94 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-10-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142488821","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}
Esteban Bustos-Caparros, Tomeu Viver, Juan F Gago, Luis Miguel Rodriguez-Rojas, Janet K Hatt, Stephanus N Venter, Bernhard M Fuchs, Rudolf Amann, Rafael Bosch, Konstantinos T Konstantinidis, Ramon Rossello-Mora
To understand how extreme halophiles respond to recurrent disturbances, we challenged the communities thriving in salt-saturated (~36% salts) ~230 L brine mesocosms to repeated dilutions down to 13% (D13 mesocosm) or 20% (D20 mesocosm) salts each time mesocosms reached salt saturation due to evaporation (for 10 and 17 cycles, respectively) over 813 days. Depending on the magnitude of dilution, the most prevalent species, Haloquadratum walsbyi and Salinibacter ruber, either increased in dominance by replacing less competitive populations (for D20, moderate stress conditions), or severely decreased in abundance and were eventually replaced by other congeneric species better adapted to the higher osmotic stress (for D13, strong stress conditions). Congeneric species replacement was commonly observed within additional abundant genera in response to changes in environmental or biological conditions (e.g. phage predation) within the same system and under a controlled perturbation of a relevant environmental parameter. Therefore, a genus is an ecologically important level of diversity organization, not just a taxonomic rank, that persists in the environment based on congeneric species replacement due to relatively high functional overlap (gene sharing), with important consequences for the success of the lineage, and similar to the success of a species via strain-replacement. Further, our results showed that successful species were typically accompanied by the emergence of their own viral cohorts, whose intra-cohort diversity appeared to strongly covary with, and likely drive, the intra-host diversity. Collectively, our results show that brine communities are ecologically resilient and continuously adapting to changing environments by transitioning to alternative stable states.
{"title":"Ecological success of extreme halophiles subjected to recurrent osmotic disturbances is primarily driven by congeneric species replacement","authors":"Esteban Bustos-Caparros, Tomeu Viver, Juan F Gago, Luis Miguel Rodriguez-Rojas, Janet K Hatt, Stephanus N Venter, Bernhard M Fuchs, Rudolf Amann, Rafael Bosch, Konstantinos T Konstantinidis, Ramon Rossello-Mora","doi":"10.1093/ismejo/wrae215","DOIUrl":"https://doi.org/10.1093/ismejo/wrae215","url":null,"abstract":"To understand how extreme halophiles respond to recurrent disturbances, we challenged the communities thriving in salt-saturated (~36% salts) ~230 L brine mesocosms to repeated dilutions down to 13% (D13 mesocosm) or 20% (D20 mesocosm) salts each time mesocosms reached salt saturation due to evaporation (for 10 and 17 cycles, respectively) over 813 days. Depending on the magnitude of dilution, the most prevalent species, Haloquadratum walsbyi and Salinibacter ruber, either increased in dominance by replacing less competitive populations (for D20, moderate stress conditions), or severely decreased in abundance and were eventually replaced by other congeneric species better adapted to the higher osmotic stress (for D13, strong stress conditions). Congeneric species replacement was commonly observed within additional abundant genera in response to changes in environmental or biological conditions (e.g. phage predation) within the same system and under a controlled perturbation of a relevant environmental parameter. Therefore, a genus is an ecologically important level of diversity organization, not just a taxonomic rank, that persists in the environment based on congeneric species replacement due to relatively high functional overlap (gene sharing), with important consequences for the success of the lineage, and similar to the success of a species via strain-replacement. Further, our results showed that successful species were typically accompanied by the emergence of their own viral cohorts, whose intra-cohort diversity appeared to strongly covary with, and likely drive, the intra-host diversity. Collectively, our results show that brine communities are ecologically resilient and continuously adapting to changing environments by transitioning to alternative stable states.","PeriodicalId":516554,"journal":{"name":"The ISME Journal","volume":"28 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-10-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142488822","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}
Siddharth Uppal, Samantha C Waterworth, Alina Nick, Heiko Vogel, Laura V Flórez, Martin Kaltenpoth, Jason C Kwan
Microbial symbionts associate with multicellular organisms on a continuum from facultative associations to mutual codependency. In the oldest intracellular symbioses there is exclusive vertical symbiont transmission, and co-diversification of symbiotic partners over millions of years. Such symbionts often undergo genome reduction due to low effective population sizes, frequent population bottlenecks, and reduced purifying selection. Here, we describe multiple independent acquisition events of closely related defensive symbionts followed by genome erosion in a group of Lagriinae beetles. Previous work in Lagria villosa revealed the dominant genome-eroded symbiont of the genus Burkholderia produces the antifungal compound lagriamide, protecting the beetle’s eggs and larvae from antagonistic fungi. Here, we use metagenomics to assemble 11 additional genomes of lagriamide-producing symbionts from seven different host species within Lagriinae from five countries, to unravel the evolutionary history of this symbiotic relationship. In each host, we detected one dominant genome-eroded Burkholderia symbiont encoding the lagriamide biosynthetic gene cluster. However, we did not find evidence for host-symbiont co-diversification, or for monophyly of the lagriamide-producing symbionts. Instead, our analyses support a single ancestral acquisition of the gene cluster followed by at least four independent symbiont acquisitions and subsequent genome erosion in each lineage. By contrast, a clade of plant-associated relatives retained large genomes but secondarily lost the lagriamide gene cluster. Our results, therefore, reveal a dynamic evolutionary history with multiple independent symbiont acquisitions characterized by a high degree of specificity, and highlight the importance of the specialized metabolite lagriamide for the establishment and maintenance of this defensive symbiosis.
{"title":"Repeated horizontal acquisition of lagriamide-producing symbionts in Lagriinae beetles","authors":"Siddharth Uppal, Samantha C Waterworth, Alina Nick, Heiko Vogel, Laura V Flórez, Martin Kaltenpoth, Jason C Kwan","doi":"10.1093/ismejo/wrae211","DOIUrl":"https://doi.org/10.1093/ismejo/wrae211","url":null,"abstract":"Microbial symbionts associate with multicellular organisms on a continuum from facultative associations to mutual codependency. In the oldest intracellular symbioses there is exclusive vertical symbiont transmission, and co-diversification of symbiotic partners over millions of years. Such symbionts often undergo genome reduction due to low effective population sizes, frequent population bottlenecks, and reduced purifying selection. Here, we describe multiple independent acquisition events of closely related defensive symbionts followed by genome erosion in a group of Lagriinae beetles. Previous work in Lagria villosa revealed the dominant genome-eroded symbiont of the genus Burkholderia produces the antifungal compound lagriamide, protecting the beetle’s eggs and larvae from antagonistic fungi. Here, we use metagenomics to assemble 11 additional genomes of lagriamide-producing symbionts from seven different host species within Lagriinae from five countries, to unravel the evolutionary history of this symbiotic relationship. In each host, we detected one dominant genome-eroded Burkholderia symbiont encoding the lagriamide biosynthetic gene cluster. However, we did not find evidence for host-symbiont co-diversification, or for monophyly of the lagriamide-producing symbionts. Instead, our analyses support a single ancestral acquisition of the gene cluster followed by at least four independent symbiont acquisitions and subsequent genome erosion in each lineage. By contrast, a clade of plant-associated relatives retained large genomes but secondarily lost the lagriamide gene cluster. Our results, therefore, reveal a dynamic evolutionary history with multiple independent symbiont acquisitions characterized by a high degree of specificity, and highlight the importance of the specialized metabolite lagriamide for the establishment and maintenance of this defensive symbiosis.","PeriodicalId":516554,"journal":{"name":"The ISME Journal","volume":"23 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-10-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142488817","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}
Lin Chen, Xue Zhao, Shelyn Wongso, Zhuohui Lin, Siyun Wang
Parasite–host co-evolution results in population extinction or co-existence, yet the factors driving these distinct outcomes remain elusive. In this study, Salmonella strains were individually co-evolved with the lytic phage SF1 for 30 days, resulting in phage extinction or co-existence. We conducted a systematic investigation into the phenotypic and genetic dynamics of evolved host cells and phages to elucidate the evolutionary mechanisms. Throughout co-evolution, host cells displayed diverse phage resistance patterns: sensitivity, partial resistance, and complete resistance, to wild-type phage. Moreover, phage resistance strength showed a robust linear correlation with phage adsorption, suggesting that surface modification-mediated phage attachment predominates as the resistance mechanism in evolved bacterial populations. Additionally, bacterial isolates eliminating phages exhibited higher mutation rates and lower fitness costs in developing resistance compared to those leading to co-existence. Phage resistance genes were classified into two categories: key mutations, characterized by nonsense/frameshift mutations in rfaH-regulated rfb genes, leading to the removal of the receptor O-antigen; and secondary mutations, which involve less critical modifications, such as fimbrial synthesis and tRNA modification. The accumulation of secondary mutations resulted in partial and complete resistance, which could be overcome by evolved phages, whereas key mutations conferred undefeatable complete resistance by deleting receptors. In conclusion, higher key mutation frequencies with lower fitness costs promised strong resistance and eventual phage extinction, whereas deficiencies in fitness cost, mutation rate, and key mutation led to co-existence. Our findings reveal the distinct population dynamics and evolutionary trade-offs of phage resistance during co-evolution, thereby deepening our understanding of microbial interactions.
{"title":"Trade-offs between receptor modification and fitness drive host-bacteriophage co-evolution leading to phage extinction or co-existence","authors":"Lin Chen, Xue Zhao, Shelyn Wongso, Zhuohui Lin, Siyun Wang","doi":"10.1093/ismejo/wrae214","DOIUrl":"https://doi.org/10.1093/ismejo/wrae214","url":null,"abstract":"Parasite–host co-evolution results in population extinction or co-existence, yet the factors driving these distinct outcomes remain elusive. In this study, Salmonella strains were individually co-evolved with the lytic phage SF1 for 30 days, resulting in phage extinction or co-existence. We conducted a systematic investigation into the phenotypic and genetic dynamics of evolved host cells and phages to elucidate the evolutionary mechanisms. Throughout co-evolution, host cells displayed diverse phage resistance patterns: sensitivity, partial resistance, and complete resistance, to wild-type phage. Moreover, phage resistance strength showed a robust linear correlation with phage adsorption, suggesting that surface modification-mediated phage attachment predominates as the resistance mechanism in evolved bacterial populations. Additionally, bacterial isolates eliminating phages exhibited higher mutation rates and lower fitness costs in developing resistance compared to those leading to co-existence. Phage resistance genes were classified into two categories: key mutations, characterized by nonsense/frameshift mutations in rfaH-regulated rfb genes, leading to the removal of the receptor O-antigen; and secondary mutations, which involve less critical modifications, such as fimbrial synthesis and tRNA modification. The accumulation of secondary mutations resulted in partial and complete resistance, which could be overcome by evolved phages, whereas key mutations conferred undefeatable complete resistance by deleting receptors. In conclusion, higher key mutation frequencies with lower fitness costs promised strong resistance and eventual phage extinction, whereas deficiencies in fitness cost, mutation rate, and key mutation led to co-existence. Our findings reveal the distinct population dynamics and evolutionary trade-offs of phage resistance during co-evolution, thereby deepening our understanding of microbial interactions.","PeriodicalId":516554,"journal":{"name":"The ISME Journal","volume":"211 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-10-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142488818","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}