深水沉积物岩心古菌群落结构对天然气水合物的指示——以南海台西南海域973-4站位为例  

The indicative effect of structures of archaeal communities at deep-water sediment cores on natural gas hydrate:A case study from Station 973-4 in the Southwest Taiwan Basin,South China Sea

作　　者：杨玉峰[1,2] 雷怀彦[1,2] 史春潇 

机构地区：[1]厦门大学近海海洋环境科学国家重点实验室 [2]厦门大学海洋与地球学院

出　　处：《天然气工业》2015年第11期119-125,共7页Natural Gas Industry

基　　金：国家自然科学基金项目"天然气水合物成藏体系中产甲烷与甲烷厌氧氧化作用生物标志物和分子生物学研究"(编号:41276046)

摘　　要：微生物产甲烷作用和甲烷厌氧氧化作用对海底天然气水合物(以下简称水合物)的形成、分解有着重要的影响,但目前有关古菌类群的代谢机理及其对水合物成藏的指示作用尚有待深入研究。为此,利用基于16S rDNA的分子生物学技术,对南海台西南海域973-4站位岩心的古菌群落结构进行了分析,并与日本海、南海神狐海域等水合物赋存、非赋存区的古菌群落结构进行了对比。结果表明:①973-4站位岩心中广古菌Methanosarcina为优势类群,在表层所占比例为50%,在硫酸盐-甲烷转换带(SMTZ)的比例为46.1%,在深层的比例为66.7%;②Methanomicrobiales为次优势类群,在表层所占比例为28.3%,在SMTZ层位为30.7%,在深层为11.1%;③上述2个古菌类群所占比例的变化趋势与海洋沉积物早期成岩过程中有机质含量、组分的变异密切相关。结论认为:①古菌群落结构与细菌、地球化学和矿物学的分析结果一致,表明973-4站位岩心下部赋存水合物;②由于古菌群落结构存在差异性,必须考虑地球化学参数和地质特征的协同作用,才能提高其对水合物成藏指示的精准性。The formation and decomposition of submarine natural gas hydrate （hereinafter hydrate for short） are greatly influenced by methanogenesis and anaerobic methane oxidation of micro organisms, so it is necessary to conduct further analysis on the metabolic mechanism of archaeal communities and its indicative effect on hydrate reservoir formation. In this paper, the structures of archaeal communities at the cores of Station 973-4 in the Southwest Taiwan Basin of South China Sea were studied by means of 16S rDNA molecular biological technologies, and then were compared with those at hydrate occurrence and non-occurrence zones in the Japan Sea and the Shenhu area of South China Sea. It is shown that Methanosarcina is the predominant community at the cores from Station 973-4, with a percentage of 50% in the surface zone, 46.1 % in the sulphate-methane transition zone （SMTZ） and 66.7 % in the deep zone. Methanomicrobiales is the secondary predominant community, with a percentage of 28.3% in the surface level, 30.7% in SMTZ and 11.1G in the deep zone. The percentage changing tendency of the above mentioned communities are closely related with the variation of organic matter content and compositions during the early diagenetic process. It is concluded that the structures of ar- chaeal communities are in accordance with the analysis results of bacteria, geochemistry and mineralogy, indicating the occurrence of hydrate at the bottom of the cores from Station 973-4. And the structures of archaeai communities are characterized by diversity, so attention shall be paid to the synergy between geochemical parameters and geologic characteristics, so that the indicative effect on hy- drate reservoir formation will be presented more accurately.

关 键 词：南海 台西南盆地 古菌多样性 日本海 神狐海域 天然气水合物 产甲烷作用 甲烷厌氧氧化作用 

分 类 号：P618.13[天文地球—矿床学]