{"title":"Anaerobic ammonium oxidation coupled to iron(III) reduction catalyzed by a lithoautotrophic nitrate-reducing iron(II) oxidizing enrichment culture.","authors":"Hong-Bin Zhang, He-Fei Wang, Jia-Bo Liu, Zhen Bi, Ruo-Fei Jin, Tian Tian","doi":"10.1093/ismejo/wrae149","DOIUrl":"10.1093/ismejo/wrae149","url":null,"abstract":"<p><p>The last two decades have seen nitrogen/iron-transforming bacteria at the forefront of new biogeochemical discoveries, such as anaerobic ammonium oxidation coupled to ferric iron reduction (feammox) and lithoautotrophic nitrate-reducing ferrous iron-oxidation (NRFeOx). These emerging findings continue to expand our knowledge of the nitrogen/iron cycle in nature and also highlight the need to re-understand the functional traits of the microorganisms involved. Here, as a proof-of-principle, we report compelling evidence for the capability of an NRFeOx enrichment culture to catalyze the feammox process. Our results demonstrate that the NRFeOx culture predominantly oxidizes NH4+ to nitrogen gas, by reducing both chelated nitrilotriacetic acid (NTA)-Fe(III) and poorly soluble Fe(III)-bearing minerals (γ-FeOOH) at pH 4.0 and 8.0, respectively. In the NRFeOx culture, Fe(II)-oxidizing bacteria of Rhodanobacter and Fe(III)-reducing bacteria of unclassified_Acidobacteriota coexisted. Their relative abundances were dynamically regulated by the supplemented iron sources. Metagenomic analysis revealed that the NRFeOx culture contained a complete set of denitrifying genes along with hao genes for ammonium oxidation. Additionally, numerous genes encoding extracellular electron transport-associated proteins or their homologs were identified, which facilitated the reduction of extracellular iron by this culture. More broadly, this work lightens the unexplored potential of specific microbial groups in driving nitrogen transformation through multiple pathways and highlights the essential role of microbial iron metabolism in the integral biogeochemical nitrogen cycle.</p>","PeriodicalId":50271,"journal":{"name":"ISME Journal","volume":" ","pages":""},"PeriodicalIF":10.8,"publicationDate":"2024-01-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11366258/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141856963","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
ISME JournalPub Date : 2024-01-08DOI: 10.1093/ismejo/wrae056
Claudia Coleine, Manuel Delgado-Baquerizo, Jocelyne DiRuggiero, Emilio Guirado, Antoine L Harfouche, Cesar Perez-Fernandez, Brajesh K Singh, Laura Selbmann, Eleonora Egidi
{"title":"Dryland microbiomes reveal community adaptations to desertification and climate change.","authors":"Claudia Coleine, Manuel Delgado-Baquerizo, Jocelyne DiRuggiero, Emilio Guirado, Antoine L Harfouche, Cesar Perez-Fernandez, Brajesh K Singh, Laura Selbmann, Eleonora Egidi","doi":"10.1093/ismejo/wrae056","DOIUrl":"10.1093/ismejo/wrae056","url":null,"abstract":"<p><p>Drylands account for 45% of the Earth's land area, supporting ~40% of the global population. These regions support some of the most extreme environments on Earth, characterized by extreme temperatures, low and variable rainfall, and low soil fertility. In these biomes, microorganisms provide vital ecosystem services and have evolved distinctive adaptation strategies to endure and flourish in the extreme. However, dryland microbiomes and the ecosystem services they provide are under threat due to intensifying desertification and climate change. In this review, we provide a synthesis of our current understanding of microbial life in drylands, emphasizing the remarkable diversity and adaptations of these communities. We then discuss anthropogenic threats, including the influence of climate change on dryland microbiomes and outline current knowledge gaps. Finally, we propose research priorities to address those gaps and safeguard the sustainability of these fragile biomes.</p>","PeriodicalId":50271,"journal":{"name":"ISME Journal","volume":" ","pages":""},"PeriodicalIF":10.8,"publicationDate":"2024-01-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11031246/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140327349","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
ISME JournalPub Date : 2024-01-08DOI: 10.1093/ismejo/wrae126
Citlali Fonseca-García, Dean Pettinga, Andrew Wilson, Joshua R Elmore, Ryan McClure, Jackie Atim, Julie Pedraza, Robert Hutmacher, Halbay Turumtay, Yang Tian, Aymerick Eudes, Henrik V Scheller, Robert G Egbert, Devin Coleman-Derr
{"title":"Defined synthetic microbial communities colonize and benefit field-grown sorghum.","authors":"Citlali Fonseca-García, Dean Pettinga, Andrew Wilson, Joshua R Elmore, Ryan McClure, Jackie Atim, Julie Pedraza, Robert Hutmacher, Halbay Turumtay, Yang Tian, Aymerick Eudes, Henrik V Scheller, Robert G Egbert, Devin Coleman-Derr","doi":"10.1093/ismejo/wrae126","DOIUrl":"10.1093/ismejo/wrae126","url":null,"abstract":"<p><p>The rhizosphere constitutes a dynamic interface between plant hosts and their associated microbial communities. Despite the acknowledged potential for enhancing plant fitness by manipulating the rhizosphere, the engineering of the rhizosphere microbiome through inoculation has posed significant challenges. These challenges are thought to arise from the competitive microbial ecosystem where introduced microbes must survive, and the absence of adaptation to the specific metabolic and environmental demands of the rhizosphere. Here, we engineered a synthetic rhizosphere community (SRC1) with the anticipation that it would exhibit a selective advantage in colonizing the host Sorghum bicolor, thereby potentially fostering its growth. SRC1 was assembled from bacterial isolates identified either for their potential role in community cohesion through network analysis or for their ability to benefit from host-specific exudate compounds. The growth performance of SRC1 was assessed in vitro on solid media, in planta under gnotobiotic laboratory conditions, and in the field. Our findings reveal that SRC1 cohesion is most robust when cultivated in the presence of the plant host under laboratory conditions, with lineages being lost from the community when grown either in vitro or in a native field setting. We establish that SRC1 effectively promotes the growth of both above- and below-ground plant phenotypes in both laboratory and native field contexts. Furthermore, in laboratory conditions, these growth enhancements correlate with the transcriptional dampening of lignin biosynthesis in the host. Collectively, these results underscore the potential utility of synthetic microbial communities for modulating crop performance in controlled and native environments alike.</p>","PeriodicalId":50271,"journal":{"name":"ISME Journal","volume":" ","pages":""},"PeriodicalIF":10.8,"publicationDate":"2024-01-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11410050/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141565019","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Chemolithoautotrophic diazotrophs dominate dark nitrogen fixation in mangrove sediments.","authors":"Shasha Wang, Lijing Jiang, Zhuoming Zhao, Zhen Chen, Jun Wang, Karine Alain, Liang Cui, Yangsheng Zhong, Yongyi Peng, Qiliang Lai, Xiyang Dong, Zongze Shao","doi":"10.1093/ismejo/wrae119","DOIUrl":"10.1093/ismejo/wrae119","url":null,"abstract":"<p><p>Diazotrophic microorganisms regulate marine productivity by alleviating nitrogen limitation. So far chemolithoautotrophic bacteria are widely recognized as the principal diazotrophs in oligotrophic marine and terrestrial ecosystems. However, the contribution of chemolithoautotrophs to nitrogen fixation in organic-rich habitats remains unclear. Here, we utilized metagenomic and metatranscriptomic approaches integrated with cultivation assays to investigate the diversity, distribution, and activity of diazotrophs residing in Zhangzhou mangrove sediments. Physicochemical assays show that the studied mangrove sediments are typical carbon-rich, sulfur-rich, nitrogen-limited, and low-redox marine ecosystems. These sediments host a wide phylogenetic variety of nitrogenase genes, including groups I-III and VII-VIII. Unexpectedly diverse chemolithoautotrophic taxa including Campylobacteria, Gammaproteobacteria, Zetaproteobacteria, and Thermodesulfovibrionia are the predominant and active nitrogen fixers in the 0-18 cm sediment layer. In contrast, the 18-20 cm layer is dominated by active diazotrophs from the chemolithoautotrophic taxa Desulfobacterota and Halobacteriota. Further analysis of MAGs shows that the main chemolithoautotrophs can fix nitrogen by coupling the oxidation of hydrogen, reduced sulfur, and iron, with the reduction of oxygen, nitrate, and sulfur. Culture experiments further demonstrate that members of chemolithoautotrophic Campylobacteria have the nitrogen-fixing capacity driven by hydrogen and sulfur oxidation. Activity measurements confirm that the diazotrophs inhabiting mangrove sediments preferentially drain energy from diverse reduced inorganic compounds other than from organics. Overall, our results suggest that chemolithoautotrophs rather than heterotrophs are dominant nitrogen fixers in mangrove sediments. This study underscores the significance of chemolithoautotrophs in carbon-dominant ecosystems.</p>","PeriodicalId":50271,"journal":{"name":"ISME Journal","volume":" ","pages":""},"PeriodicalIF":10.8,"publicationDate":"2024-01-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11474244/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141447413","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
ISME JournalPub Date : 2024-01-08DOI: 10.1093/ismejo/wrae120
Sang-Moo Lee, Roniya Thapa Magar, Min Kyeong Jung, Hyun Gi Kong, Ju Yeon Song, Joo Hwan Kwon, Minseo Choi, Hyoung Ju Lee, Seung Yeup Lee, Raees Khan, Jihyun F Kim, Seon-Woo Lee
{"title":"Rhizobacterial syntrophy between a helper and a beneficiary promotes tomato plant health.","authors":"Sang-Moo Lee, Roniya Thapa Magar, Min Kyeong Jung, Hyun Gi Kong, Ju Yeon Song, Joo Hwan Kwon, Minseo Choi, Hyoung Ju Lee, Seung Yeup Lee, Raees Khan, Jihyun F Kim, Seon-Woo Lee","doi":"10.1093/ismejo/wrae120","DOIUrl":"10.1093/ismejo/wrae120","url":null,"abstract":"<p><p>Microbial interactions impact the functioning of microbial communities. However, microbial interactions within host-associated communities remain poorly understood. Here, we report that the beneficiary rhizobacterium Niallia sp. RD1 requires the helper Pseudomonas putida H3 for bacterial growth and beneficial interactions with the plant host. In the absence of the helper H3 strain, the Niallia sp. RD1 strain exhibited weak respiration and elongated cell morphology without forming bacterial colonies. A transposon mutant of H3 in a gene encoding succinate-semialdehyde dehydrogenase displayed much attenuated support of RD1 colony formation. Through the subsequent addition of succinate to the media, we found that succinate serves as a public good that supports RD1 growth. Comparative genome analysis highlighted that RD1 lacked the gene for sufficient succinate, suggesting its evolution as a beneficiary of succinate biosynthesis. The syntrophic interaction between RD1 and H3 efficiently protected tomato plants from bacterial wilt and promoted tomato growth. The addition of succinate to the medium restored complex II-dependent respiration in RD1 and facilitated the cultivation of various bacterial isolates from the rhizosphere. Taken together, we delineate energy auxotrophic beneficiaries ubiquitous in the microbial community, and these beneficiaries could benefit host plants with the aid of helpers in the rhizosphere.</p>","PeriodicalId":50271,"journal":{"name":"ISME Journal","volume":" ","pages":""},"PeriodicalIF":10.8,"publicationDate":"2024-01-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11253211/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141477901","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
ISME JournalPub Date : 2024-01-08DOI: 10.1093/ismejo/wrae082
Wei Li, David Baliu-Rodriguez, Sanduni H Premathilaka, Sharmila I Thenuwara, Jeffrey A Kimbrel, Ty J Samo, Christina Ramon, Erik Anders Kiledal, Sara R Rivera, Jenan Kharbush, Dragan Isailovic, Peter K Weber, Gregory J Dick, Xavier Mayali
{"title":"Microbiome processing of organic nitrogen input supports growth and cyanotoxin production of Microcystis aeruginosa cultures.","authors":"Wei Li, David Baliu-Rodriguez, Sanduni H Premathilaka, Sharmila I Thenuwara, Jeffrey A Kimbrel, Ty J Samo, Christina Ramon, Erik Anders Kiledal, Sara R Rivera, Jenan Kharbush, Dragan Isailovic, Peter K Weber, Gregory J Dick, Xavier Mayali","doi":"10.1093/ismejo/wrae082","DOIUrl":"10.1093/ismejo/wrae082","url":null,"abstract":"<p><p>Nutrient-induced blooms of the globally abundant freshwater toxic cyanobacterium Microcystis cause worldwide public and ecosystem health concerns. The response of Microcystis growth and toxin production to new and recycled nitrogen (N) inputs and the impact of heterotrophic bacteria in the Microcystis phycosphere on these processes are not well understood. Here, using microbiome transplant experiments, cyanotoxin analysis, and nanometer-scale stable isotope probing to measure N incorporation and exchange at single cell resolution, we monitored the growth, cyanotoxin production, and microbiome community structure of several Microcystis strains grown on amino acids or proteins as the sole N source. We demonstrate that the type of organic N available shaped the microbial community associated with Microcystis, and external organic N input led to decreased bacterial colonization of Microcystis colonies. Our data also suggest that certain Microcystis strains could directly uptake amino acids, but with lower rates than heterotrophic bacteria. Toxin analysis showed that biomass-specific microcystin production was not impacted by N source (i.e. nitrate, amino acids, or protein) but rather by total N availability. Single-cell isotope incorporation revealed that some bacterial communities competed with Microcystis for organic N, but other communities promoted increased N uptake by Microcystis, likely through ammonification or organic N modification. Our laboratory culture data suggest that organic N input could support Microcystis blooms and toxin production in nature, and Microcystis-associated microbial communities likely play critical roles in this process by influencing cyanobacterial succession through either decreasing (via competition) or increasing (via biotransformation) N availability, especially under inorganic N scarcity.</p>","PeriodicalId":50271,"journal":{"name":"ISME Journal","volume":" ","pages":""},"PeriodicalIF":10.8,"publicationDate":"2024-01-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11126159/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140892844","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
ISME JournalPub Date : 2024-01-08DOI: 10.1093/ismejo/wrae090
Gao Chen, Yi Yang, Jun Yan, Frank E Löffler
{"title":"Metabolite cross-feeding enables concomitant catabolism of chlorinated methanes and chlorinated ethenes in synthetic microbial assemblies.","authors":"Gao Chen, Yi Yang, Jun Yan, Frank E Löffler","doi":"10.1093/ismejo/wrae090","DOIUrl":"10.1093/ismejo/wrae090","url":null,"abstract":"<p><p>Isolate studies have been a cornerstone for unraveling metabolic pathways and phenotypical (functional) features. Biogeochemical processes in natural and engineered ecosystems are generally performed by more than a single microbe and often rely on mutualistic interactions. We demonstrate the rational bottom-up design of synthetic, interdependent co-cultures to achieve concomitant utilization of chlorinated methanes as electron donors and organohalogens as electron acceptors. Specialized anaerobes conserve energy from the catabolic conversion of chloromethane or dichloromethane to formate, H2, and acetate, compounds that the organohalide-respiring bacterium Dehalogenimonas etheniformans strain GP requires to utilize cis-1,2-dichloroethenene and vinyl chloride as electron acceptors. Organism-specific qPCR enumeration matched the growth of individual dechlorinators to the respective functional (i.e. dechlorination) traits. The metabolite cross-feeding in the synthetic (co-)cultures enables concomitant utilization of chlorinated methanes (i.e. chloromethane and dichloromethane) and chlorinated ethenes (i.e. cis-1,2-dichloroethenene and vinyl chloride) without the addition of an external electron donor (i.e. formate and H2). The findings illustrate that naturally occurring chlorinated C1 compounds can sustain anaerobic food webs, an observation with implications for the development of interdependent, mutualistic communities, the sustenance of microbial life in oligotrophic and energy-deprived environments, and the fate of chloromethane/dichloromethane and chlorinated electron acceptors (e.g. chlorinated ethenes) in pristine environments and commingled contaminant plumes.</p>","PeriodicalId":50271,"journal":{"name":"ISME Journal","volume":" ","pages":""},"PeriodicalIF":10.8,"publicationDate":"2024-01-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11170663/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141181371","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Role of Type VI secretion system in pathogenic remodeling of host gut microbiota during Aeromonas veronii infection.","authors":"Xiaoli Jiang, Hanzeng Li, Jiayue Ma, Hong Li, Xiang Ma, Yanqiong Tang, Juanjuan Li, Xue Chi, Yong Deng, Sheng Zeng, Zhu Liu","doi":"10.1093/ismejo/wrae053","DOIUrl":"10.1093/ismejo/wrae053","url":null,"abstract":"<p><p>Intestinal microbial disturbance is a direct cause of host disease. The bacterial Type VI secretion system (T6SS) often plays a crucial role in the fitness of pathogenic bacteria by delivering toxic effectors into target cells. However, its impact on the gut microbiota and host pathogenesis is poorly understood. To address this question, we characterized a new T6SS in the pathogenic Aeromonas veronii C4. First, we validated the secretion function of the core machinery of A. veronii C4 T6SS. Second, we found that the pathogenesis and colonization of A. veronii C4 is largely dependent on its T6SS. The effector secretion activity of A. veronii C4 T6SS not only provides an advantage in competition among bacteria in vitro, but also contributes to occupation of an ecological niche in the nutritionally deficient and anaerobic environment of the host intestine. Metagenomic analysis showed that the T6SS directly inhibits or eliminates symbiotic strains from the intestine, resulting in dysregulated gut microbiome homeostasis. In addition, we identified three unknown effectors, Tse1, Tse2, and Tse3, in the T6SS, which contribute to T6SS-mediated bacterial competition and pathogenesis by impairing targeted cell integrity. Our findings highlight that T6SS can remodel the host gut microbiota by intricate interplay between T6SS-mediated bacterial competition and altered host immune responses, which synergistically promote pathogenesis of A. veronii C4. Therefore, this newly characterized T6SS could represent a general interaction mechanism between the host and pathogen, and may offer a potential therapeutic target for controlling bacterial pathogens.</p>","PeriodicalId":50271,"journal":{"name":"ISME Journal","volume":" ","pages":""},"PeriodicalIF":11.0,"publicationDate":"2024-01-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11014884/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140295078","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
ISME JournalPub Date : 2024-01-08DOI: 10.1093/ismejo/wrae089
Shawn M Christensen, Sriram N Srinivas, Quinn S McFrederick, Bryan N Danforth, Stephen L Buchmann, Rachel L Vannette
{"title":"Symbiotic bacteria and fungi proliferate in diapause and may enhance overwintering survival in a solitary bee.","authors":"Shawn M Christensen, Sriram N Srinivas, Quinn S McFrederick, Bryan N Danforth, Stephen L Buchmann, Rachel L Vannette","doi":"10.1093/ismejo/wrae089","DOIUrl":"10.1093/ismejo/wrae089","url":null,"abstract":"<p><p>Host-microbe interactions underlie the development and fitness of many macroorganisms, including bees. Whereas many social bees benefit from vertically transmitted gut bacteria, current data suggests that solitary bees, which comprise the vast majority of species diversity within bees, lack a highly specialized gut microbiome. Here, we examine the composition and abundance of bacteria and fungi throughout the complete life cycle of the ground-nesting solitary bee Anthophora bomboides standfordiana. In contrast to expectations, immature bee stages maintain a distinct core microbiome consisting of Actinobacterial genera (Streptomyces, Nocardiodes) and the fungus Moniliella spathulata. Dormant (diapausing) larval bees hosted the most abundant and distinctive bacteria and fungi, attaining 33 and 52 times their initial copy number, respectively. We tested two adaptive hypotheses regarding microbial functions for diapausing bees. First, using isolated bacteria and fungi, we found that Streptomyces from brood cells inhibited the growth of multiple pathogenic filamentous fungi, suggesting a role in pathogen protection during overwintering, when bees face high pathogen pressure. Second, sugar alcohol composition changed in tandem with major changes in fungal abundance, suggesting links with bee cold tolerance or overwintering biology. We find that A. bomboides hosts a conserved core microbiome that may provide key fitness advantages through larval development and diapause, which raises the question of how this microbiome is maintained and faithfully transmitted between generations. Our results suggest that focus on microbiomes of mature or active insect developmental stages may overlook stage-specific symbionts and microbial fitness contributions during host dormancy.</p>","PeriodicalId":50271,"journal":{"name":"ISME Journal","volume":" ","pages":""},"PeriodicalIF":10.8,"publicationDate":"2024-01-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11177884/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141065578","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
ISME JournalPub Date : 2024-01-08DOI: 10.1093/ismejo/wrae108
Josie F K Elliott, David V McLeod, Tiffany B Taylor, Edze R Westra, Sylvain Gandon, Bridget N J Watson
{"title":"Conditions for the spread of CRISPR-Cas immune systems into bacterial populations.","authors":"Josie F K Elliott, David V McLeod, Tiffany B Taylor, Edze R Westra, Sylvain Gandon, Bridget N J Watson","doi":"10.1093/ismejo/wrae108","DOIUrl":"10.1093/ismejo/wrae108","url":null,"abstract":"<p><p>Bacteria contain a wide variety of innate and adaptive immune systems which provide protection to the host against invading genetic material, including bacteriophages (phages). It is becoming increasingly clear that bacterial immune systems are frequently lost and gained through horizontal gene transfer. However, how and when new immune systems can become established in a bacterial population have remained largely unstudied. We developed a joint epidemiological and evolutionary model that predicts the conditions necessary for the spread of a CRISPR-Cas (clustered regularly interspaced short palindromic repeats-CRISPR-associated) immune system into a bacterial population lacking this system. We found that whether bacteria carrying CRISPR-Cas will spread (increase in frequency) into a bacterial population depends on the abundance of phages and the difference in the frequency of phage resistance mechanisms between bacteria carrying a CRISPR-Cas immune system and those not (denoted as ${f}_{Delta }$). Specifically, the abundance of cells carrying CRISPR-Cas will increase if there is a higher proportion of phage resistance (either via CRISPR-Cas immunity or surface modification) in the CRISPR-Cas-possessing population than in the cells lacking CRISPR-Cas. We experimentally validated these predictions in a model using Pseudomonas aeruginosa PA14 and phage DMS3vir. Specifically, by varying the initial ratios of different strains of bacteria that carry alternative forms of phage resistance, we confirmed that the spread of cells carrying CRISPR-Cas through a population can be predicted based on phage density and the relative frequency of resistance phenotypes. Understanding which conditions promote the spread of CRISPR-Cas systems helps to predict when and where these defences can become established in bacterial populations after a horizontal gene transfer event, both in ecological and clinical contexts.</p>","PeriodicalId":50271,"journal":{"name":"ISME Journal","volume":" ","pages":""},"PeriodicalIF":10.8,"publicationDate":"2024-01-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11285788/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141428157","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}