HR: 16:30h
AN: B44A-03    [Abstracts]
TI: Molecular Phylogeny Of Microbes In The Deep-Sea Sediments From Tropical West Pacific Warm Pool
AU: Wang, F
EM: fengpingw@yahoo.com
AF: Key lab of marine biogenetic resources, Third Institute of Oceanography, State Oceanic Administration, Xiamen, P.R.China, Daxue road 178#, Xiamen, 361005 China
AU: * Xiao, X
EM: xoxiang@yahoo.com
AF: Key lab of marine biogenetic resources, Third Institute of Oceanography, State Oceanic Administration, Xiamen, P.R.China, Daxue road 178#, Xiamen, 361005 China
AU: Wang, P
EM: wp2005@163.com
AF: Key lab of marine biogenetic resources, Third Institute of Oceanography, State Oceanic Administration, Xiamen, P.R.China, Daxue road 178#, Xiamen, 361005 China
AB: The presence and phylogeny of bacteria and archaea in five deep-sea sediment samples collected from west Pacific Warm Pool area (WP-0, WP-1, WP-2, WP-3, WP-4), and in five sediment layers (1cm-, 3cm-, 6cm-, 10cm-, 12cm- layer) of the 12-cm sediment core of WP-0 were checked and compared. The microbial diversity in the five deep-sea sediments were similar as revealed by denaturing gradient gel electrophoresis, and all of them contained members of non-thermophilic marine group I crenarchaeota as the predominant archaeal group. The composition of methylotrophs including methanotrophs, sulfate reducing bacteria in the WP-0 sediment core were further investigated by molecular marker based analysis of mxaF, pmoA, dsrAB, specific anoxic methane oxidation archaeal and sulfate reducing bacterial 16S rRNA genes. From MxaF amino acid sequence analysis, it was demonstrated that microbes belonging to α - Proteobacteria most related to Hyphomicrobium and Methylobacterium were dominant aerobic methylotrophs in this deep-sea sediment; and small percentage of type II methanotrophs affiliating closest to Methylocystis and Methylosinus were also detected in this environment. mxaF quantitative PCR results showed that in the west Pacific WP sediment there existed around 3× 10 ^4-5 methylotrophs per gram sediment, 10-100 times more than that in samples collected from several other deep-sea Pacific sediment sample, but about 10 times less than that present in samples collected from rice and flower garden soil. Diverse groups of novel archaea (named as WPA), not belonging to any known archaeal lineages were checked out. They could be placed in the euryarchaeota kingdom, separated into two distinct groups, the main group was peripherally related with methanogens, the other group related with Thermoplasma. Possible sulfate reducing bacterial related with Desulfotomaculum, Desulfacinum, Desulfomonile and Desulfanuticus were also detected in our study. The vertical distributions of WPA, archaea and bacteria along the WP-0 sediment column were determined by quantitative-PCR. It was found that bacteria dominated at all depths, the numbers of bacteria were 10- 10 ⁴ times more than those of archaea. SRB constituted a small proportion of the bacteria community (0.9%-2.9%). SRB showed the highest content in 3-cm (2.9%) and had a vertical depth related decreasing tendency along the 12cm core. The proportion of archaea versus bacteria had a depth related increasing tendency, it was lowest at the first layer (0.01%), reached highest at the 12cm- layer (10%).
DE: 0410 Biodiversity
DE: 0439 Ecosystems, structure and dynamics (4815)
DE: 0448 Geomicrobiology
SC: Biogeosciences [B]
MN: Fall Meeting 2005