奇异甲烷氧化菌Crenothrix类微生物的生态功能和底物氧化途径研究

项目名称： 奇异甲烷氧化菌Crenothrix类微生物的生态功能和底物氧化途径研究

项目编号： No.31470222

项目类型： 面上项目

立项/批准年度： 2015

项目学科： 生物科学

项目作者： 全哲学

作者单位： 复旦大学

项目金额： 86万元

中文摘要： Crenothrix是属于γ-变形菌纲的甲烷氧化细菌，但其参与甲烷氧化的关键酶基因序列却与属于β-变形菌纲的氨氧化细菌更为接近，所以被叫作奇异（unusual）甲烷氧化菌。我们基于功能基因进行微生物群落结构的分析，发现常被忽略的Crenothrix类微生物是滩涂等多个环境中最主要的甲烷/氨氧化细菌类群。本研究中,将分析Crenothrix类微生物的生态分布及其环境特点；并采用不同底物（甲烷、氨或乙烷等）和电子受体（氧气、硝酸盐、硫酸盐或三价铁等）进行实验室培养，确定Crenothrix类微生物的生长条件并阐明它们在物质循环中的生态功能；以此为基础，进一步通过持续传代培养进行定向富集，并在基因组水平解析其氧化底物的代谢途径。Crenothrix类微生物的研究,将增进人们对甲烷/氨氧化微生物类型和它们在生态环境中作用的认识，并且对甲烷氧化细菌和氨氧化细菌进化关系的研究也具有重要意义。

中文关键词： 微生物分子生态学；元基因组；甲烷氧化菌；代谢途径；富集培养

英文摘要： Crenothrix in γ-Proteobacteria is called as unusual methane oxidizing bacteria, because its functional key gene is more similar with ammonia oxidizing bacteria in β-Proteobacteria. Through the functional gene based microbial population analysis, we found that the normally ignored Crenothrix-related microorganisms are the main part of methane/ammonia oxidizing bacteria. In this study, we will confirm the distribution and their environmental characteristics of Crenothrix-related microorganisms; and incubate environmental samples in laboratory with different substrate (such as methane, ammonia or ethane) and electron acceptors (such as oxygen, sulfate, nitrate or Fe(III))to find the growth condition of Crenothrix-related microorganisms and their ecological function in nutrient cycles; based on these results, we will do targeted enrichment with subsequent subculture, and understand the substrate oxidation pathway at the genomic level. The study of Crenothrix-related microorganisms not only will extend our knowledge of methane/ammonia oxidizing bacteria and their contribution in ecological environments, but also will contribute for the understanding of evolutionary relationship of methane oxidizing bacteria and ammonia oxidizing bacteria.

英文关键词： Molecular microbial ecology;metagenome;methanotroph;metabolic pathway;enrichment