Department of Biological Sciences, State University of New York at Oswego, Oswego, New York, USA.
Department of Biological Sciences, State University of New York at Oswego, Oswego, New York, USA
Appl Environ Microbiol. 2019 Jan 9;85(2). doi: 10.1128/AEM.01882-18. Print 2019 Jan 15.
Interactions between species shape the formation and function of microbial communities. In the gut microbiota of animals, cross-feeding of metabolites between microbes can enhance colonization and influence host physiology. We examined a mutually beneficial interaction between two bacteria isolated from the gut microbiota of , i.e., and After developing an coculture assay, we utilized a genetic screen to identify genes required for enhanced growth with The screen, and subsequent genetic analyses, showed that the gene encoding pyruvate phosphate dikinase () is required for to benefit fully from coculture. By testing strains with mutations in a range of metabolic genes, we provide evidence that can utilize multiple fermentation products of Mutualism between the bacteria affects gnotobiotic ; flies associated with and showed >1,000-fold increases in bacterial cell density and significantly lower triglyceride storage than monocolonized flies. Mutation of decreased density in flies cocolonized with , consistent with the model in which employs gluconeogenesis to assimilate fermentation products as a source of carbon We propose that cross-feeding between these groups is a common feature of microbiota in The digestive tracts of animals are home to a community of microorganisms, the gut microbiota, which affects the growth, development, and health of the host. Interactions among microbes in this inner ecosystem can influence which species colonize the gut and can lead to changes in host physiology. We investigated a mutually beneficial interaction between two bacterial species from the gut microbiota of fruit flies. By coculturing the bacteria , we were able to identify a metabolic gene required for the bacteria to grow better together than they do separately. Our data suggest that one species consumes the waste products of the other, leading to greater productivity of the microbial community and modifying the nutrients available to the host. This study provides a starting point for investigating how these and other bacteria mutually benefit by sharing metabolites and for determining the impact of mutualism on host health.
物种间的相互作用塑造了微生物群落的形成和功能。在动物的肠道微生物群中，微生物之间代谢物的交叉喂养可以增强定植并影响宿主生理。我们研究了两种从果蝇肠道微生物群中分离出的细菌之间互利的相互作用，即 和 。在开发了一种 共培养测定法后，我们利用遗传筛选来鉴定增强与 共生时生长所必需的 基因。该筛选以及随后的遗传分析表明，编码丙酮酸磷酸二激酶（）的基因对于 充分受益于共培养是必需的。通过测试一系列代谢基因发生突变的菌株，我们提供了证据表明 可以利用 的多种发酵产物。细菌之间的互利共生会影响无菌的；与 和 相关的苍蝇表现出细菌细胞密度增加了 >1000 倍，并且甘油三酸酯储存量明显低于单定植的苍蝇。与 共定植时，突变降低了 的密度，这与模型一致，即 利用糖异生将 发酵产物作为碳源同化。我们提出，这些群体之间的交叉喂养是 微生物群的一个共同特征。动物的消化道是微生物群落的家园，即肠道微生物群，它会影响宿主的生长、发育和健康。这个内部生态系统中的微生物相互作用会影响哪些物种定植在肠道中，并导致宿主生理发生变化。我们研究了来自果蝇肠道微生物群的两种细菌之间互利的相互作用。通过共培养这两种细菌，我们能够鉴定出一种代谢基因，该基因对于细菌在一起生长比单独生长更好是必需的。我们的数据表明，一种细菌消耗另一种细菌的废物，导致微生物群落的生产力更高，并改变了宿主可利用的营养物质。这项研究为研究这些和其他细菌如何通过共享代谢物而相互受益以及确定共生对宿主健康的影响提供了一个起点。
