Kato Shingo, Kobayashi Chiyori, Kakegawa Takeshi, Yamagishi Akihiko
Department of Molecular Biology, Tokyo University of Pharmacy and Life Science, Hachioji, Tokyo 192-0392, Japan.
Environ Microbiol. 2009 Aug;11(8):2094-111. doi: 10.1111/j.1462-2920.2009.01930.x. Epub 2009 Apr 22.
The abundance, diversity and composition of bacterial and archaeal communities in the microbial mats at deep-sea hydrothermal fields were investigated, using culture-independent 16S rRNA and functional gene analyses combined with mineralogical analysis. Microbial mats were collected at two hydrothermal areas on the ridge of the back-arc spreading centre in the Southern Mariana Trough. Scanning electron microscope and energy dispersive X-ray spectroscopic (SEM-EDS) analyses revealed that the mats were mainly composed of amorphous silica and contained numerous filamentous structures of iron hydroxides. Direct cell counting with SYBR Green I staining showed that the prokaryotic cell densities were more than 10(8) cells g(-1). Quantitative polymerase chain reaction (Q-PCR) analysis revealed that Bacteria are more abundant than Archaea in the microbial communities. Furthermore, zetaproteobacterial cells accounted for 6% and 22% of the prokaryotic cells in each mat estimated by Q-PCR with newly designed primers and TaqMan probe. Phylotypes related to iron-oxidizers, methanotrophs/methylotrophs, ammonia-oxidizers and sulfate-reducers were found in the 16S rRNA gene clone libraries constructed from each mat sample. A variety of unique archaeal 16S rRNA gene phylotypes, several pmoA, dsrAB and archaeal amoA gene phylotypes were also recovered from the microbial mats. Our results provide insights into the diversity and abundance of microbial communities within microbial mats in deep-sea hydrothermal fields.
利用非培养的16S rRNA和功能基因分析并结合矿物学分析，对深海热液区微生物席中细菌和古菌群落的丰度、多样性及组成进行了研究。在南马里亚纳海槽弧后扩张中心海脊的两个热液区采集了微生物席。扫描电子显微镜和能量色散X射线光谱（SEM-EDS）分析表明，这些微生物席主要由无定形二氧化硅组成，并含有大量氢氧化铁丝状结构。用SYBR Green I染色进行直接细胞计数表明，原核细胞密度超过10(8) 个细胞 g(-1)。定量聚合酶链反应（Q-PCR）分析表明，在微生物群落中细菌比古菌更为丰富。此外，使用新设计的引物和TaqMan探针通过Q-PCR估计，嗜铁菌细胞在每个微生物席的原核细胞中分别占6%和22%。从每个微生物席样品构建的16S rRNA基因克隆文库中发现了与铁氧化菌、甲烷氧化菌/甲基营养菌、氨氧化菌和硫酸盐还原菌相关的系统发育型。还从微生物席中获得了多种独特的古菌16S rRNA基因系统发育型、几种pmoA、dsrAB和古菌amoA基因系统发育型。我们的研究结果为深入了解深海热液区微生物席内微生物群落的多样性和丰度提供了依据。
