Microbial metabolic mutualism in starved environments.

描述（由申请人提供）：本提案旨在实现区域计划的目标：1)支持有价值的研究；2)让本科生参与研究；3)加强非研究型大学的研究环境。该项目的目标是了解在极端饥饿下支持微生物生长的代谢活动。为了理解在饥饿环境中维持微生物群落的相互作用和过程，我们希望更好地理解微生物生态学的一个突出问题：为什么在环境中发现的大多数生物体不能在实验室中培养？这种不可培养性被认为是由于无法复制许多这些物种的苛刻生长要求，使它们在环境中存活，但在实验室条件下不可培养。通过这一提议，我们的目标是通过建立互惠的相互作用来验证我们的假设，即微生物群落在极端贫营养环境中生存，使物种能够更有效地利用进入系统的复杂营养源。虽然这种相互作用可能促进极端饥饿下的多样性，但义务互惠主义阻止了使用传统技术培育这些物种。所提出的实验旨在了解进入这些系统的可用能量的数量和类型对社区多样性和互惠主义的作用。具体目的是：1)确定微生物在极端饥饿条件下是否发生互惠相互作用，以及它们在支持群落生长中起什么作用；2)确定这种共生关系是否增加了极端饥饿下的可用能量和代谢效率，推动了群落多样性；3)通过分离以前相互依赖的细菌种类，从这些极端寡营养环境中增加以前不可培养的细菌种类的数量。通过使用多种技术来监测营养流动如何影响群落多样性，我们努力了解一些更复杂的代谢相互作用，这些代谢相互作用能够在饥饿下维持生命，同时增加可培养微生物物种的多样性和数量。我们星球上的大多数微生物仍然是不可培养和未知的。尽管如此，近年来，从这些微生物中分离出来的有益产品的数量激增，从药品到普通家用洗涤剂。该建议旨在了解支持这些微生物生长的机制，并增加可以成功分离的物种数量。

DESCRIPTION (provided by applicant): This proposal aims to accomplish the AREA program objectives of 1) supporting meritorious research; 2) exposing undergraduates to research; and 3) strengthening the research environment at non-research intensive universities. The goal of this project is to understand the metabolic activity that supports microbial growth under extreme starvation. In understanding the interactions and processes that sustain microbial communities in starved environments, we hope to better understand one of the outstanding questions of microbial ecology: why are the majority of organisms identified in the environment unculturable in the laboratory? This unculturability is presumed to be due to the inability to reproduce the fastidious growth requirements of many of these species, making them viable within the environment, but unculturable under laboratory conditions. Through this proposal, we aim to test our hypothesis that microbial communities subsist in extremely oligotrophic environments by establishing mutualistic interactions, allowing species to more efficiently utilize the complex nutrient sources entering the system. While such interactions may promote diversity under extreme starvation, obligate mutualism prevents cultivation of these species using traditional techniques. The experiments proposed are geared toward understanding the role that the amount and type of available energy entering these systems have on community diversity and mutualism. The specific aims are: 1) to determine whether microbial mutualistic interactions are occurring under extreme starvation conditions and what role they play in supporting community growth; 2) to determine whether such mutualism increases the usable energy sources and metabolic efficiency under extreme starvation, driving community diversity; and 3) to increase the number of previously unculturable bacterial species from these extremely oligotrophic environments by separating previously interdependent species. By using a combination of techniques to monitor how nutrient flow affects community diversity, we endeavor to understand some of the more complex metabolic interactions capable of supporting life under starvation, while increasing the diversity and number of culturable microbial species. The majority of microbial life on our planet remains unculturable and unknown. Nonetheless, in recent years there has been an upsurge in the number of beneficial products, from pharmaceuticals to common household detergents, isolated from these organisms. This proposal aims to understand the mechanisms that support the growth of such microorganisms and increase the number of species that can be successfully isolated.