European Molecular Biology Laboratory, Heidelberg 69117, Germany.
Institute of Molecular Systems Biology, ETH-Zürich, Zürich 8093, Switzerland.
Cell Syst. 2017 Oct 25;5(4):345-357.e6. doi: 10.1016/j.cels.2017.09.002. Epub 2017 Sep 27.
Many microorganisms live in communities and depend on metabolites secreted by fellow community members for survival. Yet our knowledge of interspecies metabolic dependencies is limited to few communities with small number of exchanged metabolites, and even less is known about cellular regulation facilitating metabolic exchange. Here we show how yeast enables growth of lactic acid bacteria through endogenous, multi-component, cross-feeding in a readily established community. In nitrogen-rich environments, Saccharomyces cerevisiae adjusts its metabolism by secreting a pool of metabolites, especially amino acids, and thereby enables survival of Lactobacillus plantarum and Lactococcus lactis. Quantity of the available nitrogen sources and the status of nitrogen catabolite repression pathways jointly modulate this niche creation. We demonstrate how nitrogen overflow by yeast benefits L. plantarum in grape juice, and contributes to emergence of mutualism with L. lactis in a medium with lactose. Our results illustrate how metabolic decisions of an individual species can benefit others.
许多微生物生活在群落中，并依赖于群落成员分泌的代谢物来生存。然而，我们对种间代谢依赖性的了解仅限于少数具有少量交换代谢物的群落，而对于促进代谢交换的细胞调节则知之甚少。在这里，我们展示了酵母如何通过内源性、多组分的交叉喂养来促进乳酸细菌的生长，这种方式在易于建立的群落中很常见。在富含氮的环境中，酿酒酵母通过分泌一组代谢物（特别是氨基酸）来调整其代谢，从而使植物乳杆菌和乳酸乳球菌得以生存。可用氮源的数量和氮分解代谢物抑制途径的状态共同调节这种小生境的创造。我们证明了酵母产生的氮溢出如何使植物乳杆菌在葡萄汁中受益，并有助于与乳糖培养基中的乳酸乳球菌形成共生关系。我们的研究结果说明了一个物种的代谢决策如何使其他物种受益。
