Phylogeny of Bacteria in Deep-sea Sediments from West Pacific Warm Pool

Phylogenetic studies based on 16S rDNA gene sequence analysis,together with bacterial cultivation were used to study the bacteria diversity in five sites of deep sea sediment from west Pacific warm pool.Denaturing gradient gel electrophoresis(DGGE) profiles reveal the similar bacteria populations in sediments from five sites.16S rDNA gene sequence analyses reveal that all clones fall in proteobacteria(in subdivision gamma-,alpha-,beta-,delta-),14.03% clones are related with sulfur metabolism,indicating a relative high activity of sulfur metabolism;32 strains isolated from the samples belong to two divisions: proteobacteria(in subdivision gamma-,beta-) and gram-positive bacteria.Gamma-proteobacteria dominated the bacterial community of five sites indicates the widely distributed of gamma-proteobacteria in Pacific Ocean.Majority of the bacterial strains are able to secrete diversity cold adaptive hydrolytic enzymes into the medium at 4 ℃,indicates the relatively high metabolic activity in west Pacific Ocean.