MO: Functional Genomic Investigations of Dissolved Organic Carbon Cyling at the Sapelo Island Microbial Observatory

海洋细菌降解沿海海水中溶解的有机碳是海洋碳循环的一个重要过程。然而，这一重要过程的细节似乎极其复杂。组成溶解有机碳（DOC）池的数千种不同的化合物和参与其代谢的数千种细菌在很大程度上是未知的，这极大地阻碍了了解沿海海洋中碳的命运的努力。这反过来又阻碍了海洋变化中碳循环预测模型的发展。克服这一障碍需要环境功能基因组学方法。该项目将利用乔治亚州萨皮罗岛LTER站点细菌群落的基因表达模式，确定在沿海海洋中被同化和代谢的陆源和海洋来源的有机物的成分。在生态系统输入最明显的时候，通过直接从海水中测序表达基因，可以识别DOC供应和通量的模式。从沿海群落培养的模式菌株的表达研究将用于确定单个碳化合物代谢的生化途径，并确定从海洋DOC池中优先运输和代谢的化合物。Sapelo岛微生物观测站项目将提高对陆地边缘生态系统在全球碳循环中的作用的理解，解决细菌介导的细胞水平活动如何影响主要的生物地球化学过程。它将为学生和博士后提供微生物生物地球化学和生态基因组学的跨学科培训机会，并将为有前途的高中生物学生提供微生物生物学的研究经验，扩大未被充分代表的群体在科学领域的参与。该项目将为微生物生态学家开发新的信息学方法，将分子序列数据与环境背景信息结合起来，并将与科学界公开共享数据库和生物信息学工具。

Degradation by marine bacteria of the organic carbon dissolved in coastal seawater is a major process in the ocean carbon cycle. However, the details of this important process seem hopelessly complex. The thousands of distinct compounds that make up this dissolved organic carbon (DOC) pool and the thousands of bacterial species that participate in its metabolism are largely unknown to science, and this greatly impedes efforts to understand the fate of carbon in coastal oceans. In turn, this hinders development of predictive models of carbon cycling in a changing ocean. Overcoming this impediment requires an environmental functional genomics approach. This project will use gene expression patterns in bacterial communities at the Sapelo Island, GA LTER site to identify the components of terrestrial- and marine-derived organic matter that are assimilated and metabolized in the coastal ocean. By sequencing expressed genes directly from seawater at times when ecosystem inputs are the most distinct, the patterns of DOC supply and flux will be discerned. Expression studies of model bacterial strains cultured from coastal communities will be used to identify the biochemical pathways for metabolism of individual carbon compounds and determine the compounds that are preferentially transported and metabolized from the marine DOC pool. The Sapelo Island Microbial Observatory project will improve understanding of the role of land-margin ecosystems in the global carbon cycle, addressing how cellular-level activities mediated by bacteria affect major biogeochemical processes. It will provide opportunities for interdisciplinary training in microbial biogeochemistry and ecological genomics to students and postdoctoral associates, and will sponsor a research experience in microbial biology for promising high school biology students, broadening the participation of underrepresented groups in science. This project will develop novel informatics approaches for microbial ecologists that couple molecular sequence data with environmental context information, and will openly share databases and bioinformatics tools with the scientific community.