Host-derived amino acids support the proliferation of symbiotic bacteria
Host-derived amino acids support the proliferation of symbiotic bacteria
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DOI：
10.1073/pnas.95.4.1818
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发表时间：
1998-02-17
影响因子：
11.1
通讯作者：
Ruby, EG
中科院分区：
文献类型：
--
作者：
Graf, J;Ruby, EG
动物通常被各种细菌共生体定殖，其中许多是寄生的，在许多情况下，甚至对其宿主的正常发育和生长至关重要。作为交换，宿主必须提供足够的营养物质，以支持其微生物群落的增殖和持久性。在这项调查中，我们已经研究了这样的营养环境，通过确定的共生能力的营养缺陷型突变体的生物发光细菌弧菌fischeri，并已证明，宿主鱿鱼Euprymna candiopes提供至少9个氨基酸的共生V. fischeri存在于其发光器官的生长培养。我们还收集并分析了共生体所在的该器官的细胞外液，并证实其含有大量的氨基酸。综合结果表明，宿主来源的游离氨基酸以及肽或蛋白质是支持共生体生长的氨基酸的来源。这项工作描述了一种技术来采样的共生体及其周围的环境，而不受宿主组织成分的污染，并结合分子遗传学研究，允许表征的营养条件，支持合作的动物-细菌共生。
Animals are typically colonized by diverse bacterial symbionts, many of which are commensal and, in numerous cases, even essential for their host's proper development and growth. In exchange, the host must supply a sufficient array and quantity of nutrients to support the proliferation and persistence of its microbial community. In this investigation, we have examined such a nutritional environment by determining the symbiotic competence of auxotrophic mutants of the bioluminescent bacterium Vibrio fischeri, and have demonstrated that the host squid Euprymna scolopes provides at least 9 aa to the growing culture of symbiotic V. fischeri present in its light-emitting organ. We also collected and analyzed the extracellular fluid from this organ, in which the symbionts reside, and confirmed that it contained significant amounts of amino acids, The combined results suggested that host-derived free amino acids, as well as peptides or proteins, are a source of the amino acids that support the growth of the symbionts. This work describes a technique to sample the symbionts and their surrounding environment without contamination by host tissue components and, in combination with molecular genetic studies, allows the characterization of the nutritional conditions that support a cooperative animal-bacterial symbiosis.