南海北部九龙甲烷礁冷泉表层沉积物的微生物群落结构和宏基因组学研究

项目名称： 南海北部九龙甲烷礁冷泉表层沉积物的微生物群落结构和宏基因组学研究

项目编号： No.41476104

项目类型： 面上项目

立项/批准年度： 2015

项目学科： 天文学、地球科学

项目作者： 王勇

作者单位： 中国科学院深海科学与工程研究所

项目金额： 91万元

中文摘要： 我国南海北部陆坡含有大量甲烷水合物。甲烷气体释放到水体的过程中被微生物固定吸收并形成海底冷泉生态系统。但是，微生物参与的甲烷厌氧和有氧氧化在表层沉积物是如何进行的依然是一个重要科学问题。本项目将对南海九龙甲烷礁附近的一个冷泉区进行微生物群落结构和宏基因组学研究。利用对核糖体RNA基因的高通量测序，将对四个表层沉积物中参与甲烷氧化相关的群落进行解析和比较。通过对这些层面的微生物宏基因组的研究，将进一步解释甲烷厌氧氧化与氮循环和硫循环的耦合关系，以及与最上层甲烷有氧氧化之间的协同关系。并且将利用各个层面的微生物宏转录组信息来验证宏基因组分析获得的结果。最后，还将重点分离一些特有优势微生物的基因组，并研究南海特有甲烷氧化功能基因及其可能来源。这项研究将揭示南海冷泉区微生物介导的基本元素循环过程的分子机制，为探寻南海陆坡甲烷水合物蕴藏区域和保护我国海底生态系统提供依据。

中文关键词： 海洋微生物；微生物多样性；群落结构；碳循环；分子机制

英文摘要： The subseafloor of the northern South China Sea is rich in methane hydrate. The methane released from the hydrate will be consumed by microbes, which often leads to a cold seep ecosystem. However, how the microbes take part in the anaerobic and aerobic methane oxidation in the surface sediments is still an important scientific question. This project will study microbial communities and metagenomes of a cold seep near Jiu Long methane reef. Using pyrosequenced ribosomal RNA gene amplicons, we will uncover the composition of the communities and estimate species diversity in four surface sediment layers of the cold seep. Particularly, unique microbial groups will be examined to learn their taxonomic position. Metagenomic and metatranscriptomic analyses will help to elucidate the relationships between anaerobic methane oxidation and sulfur and nitrogen cycles in the different layers. This project will also help to understand the competition between anaerobic and aerobic methane oxidation processes at the uppermost surface sediment. Draft genomes of some microbial strains of interest will be reassembled to cast lights on their unique roles and evolutionary positions in subseafloor of South China Sea. This project may allow us to understand the molecular mechanisms of carbon, sulfur and nitrogen cycles mediated by microbes in cold seep.The microbial characteristics of the cold seep system in this project will help to explore methane hydrate regions in the South China Sea and to establish rules to protect the subseafloor ecosystem.

英文关键词： marine microbiology;biodiversity;microbial community;carbon cycle;molecular mechanism