本项目拟选择我国南海神狐、东沙海域及其冷泉区，提取沉积物中DNA，运用16S rRNA，PCR扩增，RFLP等现代分子生物学技术，建立研究区16SrDNA宏基因库，查明其物种多样性和优势菌群，分离培养甲烷代谢菌群，模拟其发育和产气过程；同时对沉积物有机质萃取和组分分离，应用GC-MS和Delta Plus XP进行有机组分和单体烃同位素组成分析，进而筛选对微生物产甲烷以及厌氧氧化作用有指示性的生物标志物；结合沉积物中自生矿物分析与总硫（TS）、硫同位素组成（δ34S）以及总铁与铁的价态变化等关键地化指标，了解天然气水合物赋存区成藏体系中微生物种群与产甲烷作用（MOG）、甲烷厌氧氧化作用（AOM）和硫酸盐还原作用（SR）之间的相互作用内在关系，揭示微生物菌群对天然气水合物成藏过程的影响，对丰富我国天然气水合物成藏理论具有十分重要的意义，为我国天然气水合物勘探开发提供科学依据。

We plan to choose Shenhu, Dongsha sea area and their cold-seep areas in the Northern South China sea as the study area, extract DNA from sediments, use modern molecular biology techniques, such as 16SrRNA, PCR amplification, RFLP, to establish 16SrDNA metagenomic library, find out the species diversity and the dominant microflora, separate and culture the methanogenic flora, simulate the process of their development. At the same time, we use GS-MS and Delta Plus XP to detect the organic components extracted from sediments and determine their isotope composition, then screen biomarkers which are indicative of methanogenesis and Anaerobic methane oxidation. Combined with authigenic mineral analysis and some geochemical indicators such as total sulfur (TS), sulfur isotope composition (δ34S), total iron and the variation of iron valence, do comprehensive analysis to understand the intrinsic relationship between microbial populations and methanogenesis (MOG), anaerobic methane oxidation (AOM), sulfate reduction (SR), reveal the impact of microbial community on accumulation process of gas hydrate. These are of great significance on theoretical system of gas hydrate formation, and would provide scientific basis for China's gas hydrate exploration and development.