东、西太平洋深海沉积物细菌多样性研究

IOCAS-IR > 海洋环流与波动重点实验室

	东、西太平洋深海沉积物细菌多样性研究
其他题名	Bcterial diversity of deep-sea sediments from the East and West Pacific Ocean.
	陈明娜
学位类型	博士
	2007-06-14
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	东太平洋西太平洋深海沉积物细菌多样性垂直分布 16s Rrna基因火山灰
摘要	深海生物圈有着不同于陆地和浅海的典型特点，例如高压、低温、永久黑暗及寡营养，并且深海微生物具有特殊的代谢途径及庞大的生物量，这使得深海成为一个巨大的有待开发利用的生物资源宝库。本文研究的样品分别取自东太平洋E272站位(12°36’39"N, 104°19’28"W)和西太平洋Ph05-5站位(16°04’93"N, 124º34’48"E)。E272站位距离东太平洋13°N海隆45km，水深3 191m；而Ph05-5站位地处西菲律宾海盆，在黑潮源区附近，位于西太平洋暖池区边缘，水深3 382m，并且Ph05-5岩芯一共包含了五个明显的火山灰层。本文采用了末端限制性片段长度多态性分析（T-RFLP）和16S rRNA 基因文库分析的方法在小尺度上对东太平洋E272站位的沉积物样品进行细菌群落结构的研究。研究结果表明沉积物细菌群落结构在小尺度上存在明显的垂直变化。系统进化分析表明，该沉积物样品的细菌多样性较高，共包含9个主要的门类，包括变形菌门、绿弯菌门（绿色非硫细菌）、浮霉菌门、酸杆菌门、放线菌门（高G+C革兰氏阳性菌）、拟杆菌门、硝化螺旋菌门、以及两个待定的门类OP8和TM6。其中变形菌门细菌是一类在海洋中非常常见的细菌，广泛分布于各个海洋环境，在我们的文库当中发现了变形菌门的三个纲，包括α-、-、-变形菌纲。本项研究充分表明该沉积物环境中具有较高的细菌多样性，在小尺度上细菌群落垂直分布明显，其结果也可从侧面反映深海沉积物近表层处的环境条件在小尺度上的垂直变化显著。对西太平洋暖池区沉积物样品的细菌群落的研究也采用16S rRNA 基因文库分析的方法。系统进化分析表明该沉积物样品细菌的多样性相对较低，一共包含了六个不同的门类，包括变形菌门、浮霉菌门、放线菌门、厚壁菌门（低G+C革兰氏阳性菌）、绿弯菌门、酸杆菌门。在这个沉积物样品中也发现了变形菌门的三个纲包括α-、-和-变形菌纲。聚类分析和系统进化分析都表明表层的细菌群落同其它8层的细菌群落存在明显的差异，并且其它8层包括5个火山灰层和3个远洋粘土层的细菌群落结构差异不大，推测火山灰成分不仅对火山灰层的细菌群落产生影响，而且可能通过扩散对整个沉积物的微生物群落结构都产生影响。表层可能由于沉积时间较晚所以受影响相对较小或表层本身不同于较深层次的理化条件而使表层群落存在较大差异。对东、西太平洋不同环境下的两个深海沉积物样品的细菌多样性进行比较，结合其它研究发现变形菌门细菌在不同深海环境中都普遍存在，是深海不同环境的广适类群。另外，两个环境中的细菌多样性存在很大差异，东太平洋沉积环境中的细菌多样性要远高于西太平洋沉积环境中的细菌多样性，推测其最可能的原因是西太平洋沉积物火山灰成分对细菌群落的影响，致使其细菌群落与东太平洋远洋粘土沉积物细菌群落产生很大差异；另外，不同洋区的环境差异也应该是造成细菌群落差异的一个重要方面。
其他摘要	Due to the special environment characteristics of the deep-sea such as cold, high pressure, dark and poor organic carbon, the biosphere in the deep-sea environments was markedly different from the continent and the shallow sea. In addition, because of the rich abundance and special metabolism pathways of microorganisms inhabiting in the deep-sea environments, the deep-sea has been considered as an important reservoir of biological resources for exploration. The sediment samples used in this study were collected from the E272 site in the East Pacific Ocean (12°36’39"N, 104°19’28"W) and the Ph05-5 site of the West Pacific Ocean (16°04’93"N, 124º34’48"E). The E272 site was 45 km from the East Pacific Rise 13°N at a depth of 3 191 m. The Ph05-5 site at a depth of 3 382 m was situated at the headstream area of Kuroshio in the West Philippine Basin and was in the margin area of the West Pacific warm pool. This sediment core recovered from the Ph05-5 site was mainly composed of pelagic clay and five buried volcanic layers. Fine-scale bacterial vertical distribution of the 40cm depth sediment core recovered from the E272 site in the East Pacific Ocean were investigated by using methods of T-RFLP and 16S rRNA gene clone library analyses. Cluster analyses of T-RFs showed that bacterial phylotypes shifted with depth even in 40 cm sediment. Diversity of bacteria was detected in this sediment environment and at least 9 major lineages of the bacteria domain were obtained. They are the phyla of the Proteobcteria, Planctomycetes, Actinobacteria (high G+C Gram-positive bacteria), Bacteroidetes, Chloroflexi, Acidobacteria, Nitrospirae, and candidate division OP8, candidate division TM6. The division of the Proteobcteria contained three subdivisions including the alpha-, gamma- and delta-Proteobateria subdivisions in our libraries and the Proteobcteria bacteria were common in different deep-sea environments. The analyses indicated the relatively high diversity of bacteria in this sediment environment and the shift of bacterial communities with depth should also indicate changes of physichemical properties on fine scale of sediments close to surface. The bacterial community of the sediment samples collected from the Ph05-5 site of the West Pacific Ocean was also analyzed by using the 16S rRNA gene clone library analysis method. Phylogenetic analyses showed that the diversity of the bacteria obtained from this sediment core was low comparatively. There were 6 phyla obtained from our libraries including the phyla of Proteobcteria, Planctomycetes, Actinobacteria (high G+C Gram-positive bacteria), Firmicutes (low G+C Gram-positive bacteria), Chloroflexi, and Acidobacteria. Three subdivisions of the Proteobcteria division including the subdivisions of the alpha-, gamma- and delta-Proteobateria were also detected in this sediment core. Cluster analysis and phylogenetic analyses both showed that the bacterial communities occurring in the surface layer were markedly different from the other eight deeper layers and there were no obvious differences of the communities presenting in the deeper 8 layers including 3 pelagic clay layers and five buried volcanic ash layers. The discovery indicated that the volcanic ash dispersed in deep-sea sediment would not only affect the microbial community inhabiting in the volcanic ash layers but would influence the whole sediment due to the diffusion of volcanic ash materials along with the burial times. It was possible that due to the sedimentation time of the sediment surface layer was later than the deeper layers, the bacterial community was influenced by the volcanic ash materials less than the other deeper layers or due to the differerent physiochemical properties of the sediment surface with the deeper layers, the bacterial community in surface layer were special. Compare analyses of the bacterial diversity of the two deep-sea sediment cores recovered from the East Pacific Ocean and the West Pacific Ocean as well as bacterial diverisity in other sediment environments showed that the Proteobactia phylum bacteria were common in different deep-sea environments. The analyses also indicated that there were marked differences of bacterial communities between the samples recovered from the East Pacific Ocean and the West Pacific Ocean. The bacterial diversity of the East Pacific Ocean sediment was higher than the bacterial diversity of the West Pacific Ocean sediments. It is possible that the volcanic ash materials dispered in sediment recovered from the West Pacific Ocean was a major influence factor. In addition, the different environment characteristics of different Ocean may be an important factor too.
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/337002/1543
专题	海洋环流与波动重点实验室
推荐引用方式 GB/T 7714	陈明娜. 东、西太平洋深海沉积物细菌多样性研究[D]. 海洋研究所. 中国科学院海洋研究所,2007.

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