MICROBIAL METABOLIC MUTUALISM UNDER EXTREME STARVATION

这个子项目是许多利用资源的研究子项目之一 由NIH/NCRR资助的中心拨款提供。子项目的主要支持 而子项目的主要调查员可能是由其他来源提供的， 包括其它NIH来源。 列出的子项目总成本可能 代表子项目使用的中心基础设施的估计数量， 而不是由NCRR赠款提供给子项目或子项目工作人员的直接资金。 我的项目的目标是了解极端饥饿下支持微生物生长的代谢活动。在了解饥饿环境中维持微生物群落的相互作用和过程时，我们希望更好地理解微生物生态学的一个突出问题：为什么环境中鉴定的大多数生物体在实验室中无法培养？这种不可培养性被认为是由于无法重现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。通过这个提议，我们的目标是测试我们的假设，即微生物群落通过建立互惠互动，使物种更有效地利用进入系统的复杂营养源，在极端贫营养环境中生存。虽然这种相互作用可能会在极端饥饿的情况下促进多样性，但专性互利主义阻止了使用传统技术培育这些物种。提出的实验是为了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利共生的作用。具体目标是：1）确定在极端饥饿条件下是否发生微生物互利共生相互作用以及它们在支持群落生长中发挥什么作用; 2）确定这种互利共生是否增加了极端饥饿下的可用能量来源和代谢效率，从而推动群落多样性;和3）通过分离以前相互依赖的细菌，物种通过使用一系列技术来监测营养流如何影响群落多样性，我们奋进了解一些更复杂的代谢相互作用，这些相互作用能够在饥饿条件下支持生命，同时增加可培养微生物物种的多样性和数量。

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. Primary support for the subproject and the subproject's principal investigator may have been provided by other sources, including other NIH sources. The Total Cost listed for the subproject likely represents the estimated amount of Center infrastructure utilized by the subproject, not direct funding provided by the NCRR grant to the subproject or subproject staff. The goal of my 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.