EAGER: Coordination of respiratory gene transcription and respiration in cultivated marine bacteria

异养细菌约占海洋呼吸作用的一半，它们是溶解有机物质的主要消费者，将大约80%的同化有机碳转化为二氧化碳。对微生物群落结构的详细研究表明，一个高度多样化的微生物群落必须负责海洋中有机物质的转化。最近的研究表明，大多数与生长有关的活动都与海洋中数量相当少的大量细菌有关。然而，尚不清楚同样的观察结果是否适用于海洋中有机碳的主要命运——呼吸作用。我们目前缺乏工具来评估特定微生物的呼吸作用，并将特定分类群与它们对碳转化和碳循环的贡献联系起来。这个项目的目的是开发一种工具来了解细菌群对细菌呼吸的贡献。拟议的工作将确定氧化磷酸化基因的转录水平和海洋细菌呼吸速率之间的关系。以培养为基础的工作是开发亚转录组学工具解决关于细菌多样性在海洋碳循环中的作用的生态问题的必要前提。该项目将包括用纯培养物进行恒化和批量培养研究，以及用天然的河口细菌群落进行孵化实验。实验室实验将检查海洋中重要的异养细菌，如SAR11支系的泛绿杆菌（Pelagibacter ubique）和玫瑰杆菌支系的绿杆菌（Ruegeria pomeroyi）。现有的基因组序列将进行分析，以解决呼吸基因的系统发育分辨力。本提案的总体目标是确定呼吸基因转录物丰度与呼吸速率之间的关系，细菌分类群定义在不同的系统发育距离。该项目将涉及一名本科生的暑期研究项目。实验室之旅向公众开放（每年约有1000名游客），刘易斯校区的所有实验室都参与了海岸日，这是一个每年吸引约10,000名游客的开放日。这些研究的结果也将提交给湖沼学和海洋学电子讲座（www.aslo.org/lectures）。这份电子期刊提供了一个平台，将该项目的成果提供给更广泛的学术界，包括本科教学机构。

Heterotrophic bacteria account for about half of the respiration in the oceans and they are the main consumers of dissolved organic materials, converting approximately 80% of assimilated organic carbon to carbon dioxide. Detailed examinations of the structure of microbial communities reveal that a highly diverse community of microorganisms must be responsible for the conversion of organic materials in the oceans. Recent studies suggest that most of growth-related activity is associated with a rather small number of abundant bacteria in the oceans. It is unclear, however, if the same observation applies to respiration, the dominant fate of organic carbon in the oceans. We currently lack tools for assessing respiration by specific microbes and for linking specific taxa with their contribution to carbon conversion and to carbon cycling. The aim of this project is to develop a tool for understanding the contribution of bacterial groups to bacterial respiration. The proposed work will determine the relationship between transcription levels of oxidative phosphorylation genes and respiration rates in cultivated marine bacteria. The culture-based work is a necessary prerequisite to develop a metatranscriptomic tool for addressing ecological questions about the role of bacterial diversity in ocean carbon cycling. The project will include chemostat and batch culture studies with pure cultures and an incubation experiment with a naturally community of estuarine bacteria. Laboratory experiments will examine important heterotrophic bacteria in the oceans such as Pelagibacter ubique of the SAR11 clade and Ruegeria pomeroyi of the Roseobacter clade. Existing genome sequences will be analyzed to address the phylogenetic resolving power of respiration genes. The overarching goal of this proposal is to determine the relationship between abundances of respiration gene transcripts and respiration rates for bacterial taxa defined at different phylogenetic distances.The project will involve an undergraduate in a summer research project. Laboratory tours are open to the public (about 1000 visitors per year), and all laboratories at the Lewes campus are involved in Coast Day, an annual open house that attracts about 10,000 visitors. The results of these studies will also be submitted to Limnology and Oceanography E-Lectures (www.aslo.org/lectures). This electronic journal provides a platform to make results of this project available to the wider academic community, including undergraduate teaching institutions.