鄂霍次克海天然气水合物区柱状沉积物LV39-18H微生物多样性研究

IOCAS-IR > 海洋环流与波动重点实验室

	鄂霍次克海天然气水合物区柱状沉积物LV39-18H微生物多样性研究
其他题名	Diversity of microbes in the gas hydrate-bearing column sediment LV39-18H sampled at the base of the Okhotsk Sea
	高远
学位类型	博士
	2008-04-11
学位授予单位	中国科学院海洋研究所
学位授予地点	海洋研究所
关键词	冷泉沉积物 16s Rrna基因文库微生物多样性环境因子鄂霍次克海
摘要	冷泉是指温度接近于海水，而以高于周围水环境浓度的烃类化合物（主要为甲烷）、硫化物或二氧化碳为主要成分，受地质构造或压力梯度作用渗出沉积物表层的流体。对冷泉沉积物中微生物群落的调查，有助于认识该极端环境中某些生理未知微生物类群的功能并理解微生物活动对整个系统的影响。本文对从鄂霍次克海冷泉区采集获得的沉积物样品按深度划分得到的11个断层中的6个断层进行了总基因组的提取，利用16S rDNA作为分子标记，构建克隆文库并结合总有机碳、总氮、硫等环境因子对该样品中的细菌和古菌群落结构沿沉积物断层的分布情况进行研究，结果显示该沉积物中的细菌和古菌均具有高度多样性且显示出明显的成层分布： 1.细菌群落主要来自10个细菌门，优势门类为绿弯菌、未定门JS1、γ-、δ-变形菌，同时还发现浮霉菌、未定门OP8、放线菌、酸杆菌、拟杆菌、疣微菌的存在。我们还在分布于表层沉积物δ-变形菌类群中发现了占该层群落15%以上的SRB（硫酸盐还原菌）类群，这强烈提示着该沉积物环境中存在着AOM（甲烷厌氧氧化）过程。 2.古菌类群主要划分为DSAG、MBG-D、MCG、MGI、MBG-A和MHVG等类群。其中MBG-D类群沿断层的垂直分布与沉积物中硫含量表现出相似的变化趋势，这提示MBG-D类群可能参与该环境中硫相关的地质化学过程。
其他摘要	Cold seeps are characterized by the seepage of fluids and elevated concentration of hydrocarbon (methane mainly), sulfide and carbon dioxide. Geological structure and/or pressure gradient conduce to the seepage. The characterization of microbial communities within sediment from cold seep is essential to understand physiologies of some novel groups and contributions of microbial activities in the extreme environment. We studied on a sediment core sample from the Okhotsk Sea. Total genomic DNA was extracted from 6 layers of 11 and 16S rDNA clone libraries were constructed to investigate the composition of bacterial and archaeal communities combining the surveys of environmental factors such as total organic carbon, total nitrogen and sulfur. Results revealed that both bacterial and archaeal communities displayed diversified composition and clearly stratified distribution: Clones of bacterial communities were from 10 bacterial phyla and some were unclassified sequences. Chloroflexi, candidate division JS1, γ-,δ- proteobacteria were the predominant groups and members of Planctomycetes, candidate division OP8, Actinobacteria, Acidobacteria, Bacteroidetes, Verrucomicrobia were also found in our sample. Additionally, we found SRB (sulfate-reduction bacteria) with a percentage more than 15% in the library of topmost layer which strongly suggest the geochemical process AOM (Anerobic oxidation of methane). Clones of archaeal libraries were mainly divided into six groups: DSAG, MBG-D, MCG, MGI, MBG-A and MHVG. Along the sediment core, the percentage of MBG-D showed obvious relevance with concentration of sulfur, which gives us the suggestion that the group MBG-D may participate in sulfur-related geochemical process in sediment environment in the Okhotsk Sea.
页数	62
语种	中文
文献类型	学位论文
条目标识符	http://ir.qdio.ac.cn/handle/337002/1335
专题	海洋环流与波动重点实验室
推荐引用方式 GB/T 7714	高远. 鄂霍次克海天然气水合物区柱状沉积物LV39-18H微生物多样性研究[D]. 海洋研究所. 中国科学院海洋研究所,2008.

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