Yangtze Delta, The Depositional Environment Bacterial Diversity In The East China Sea And Near The West Pacific Ocean Polycyclic Aromatic Hydrocarbons Degrading Bacteria Research

Part one Diversity of sediment bacteria of the Changjiang Estuary and its adjacent water as determined via 16S rRNA gene clone library analysesEstuary is a complicated and special natural complex. Changjiang Estuary and its adjacent water of the continental shelf are China's important area have always been known for their high productivity. Estuary is a special water environment mixed with the freshwater and marine salt water, the environmental factor of the reaction and change in river and sea is different.The sediment samples used in this study were collected from 4 stations(31°N-32°N, 122°E-124°E) in the Changjiang Estuary and its adjacent waters in July 2006.Diversity of bacteria was detected in this sediment environment and at least 17 major lineages of the bacteria domain were obtained. They are the phyla of the Proteobacteria(α-,β-,γ-,δ-andε- Proteobateria subdivisions), Bacteroidetes, Deferribacteres , Firmicutes, Planctomycetes, Actinobacteria (high G+C Gram-positive bacteria), Acidobacteria, Chloroflexi, Nitrospira, Fusobacteria, Verrucomicrobia, Spirochete and candidate division OP11, candidate division SW3, candidate division NKB19, candidate division OP3, candidate division GN09. The division of the Proteobcteria contained five subdivisions includingα-,β-,γ-,δ- andε-Proteobateria subdivisions in our libraries and the Proteobcteria bacteria were common in different deep-sea environments. 16S rDNA gene sequences that we got are different from the known bacteria 16S rDNA sequences from GenBank, the results showed that in the Changjiang Estuary and its adjacent water have high sediment microbial diversity and potential of unique microbial resources. Part two Islation of a PAHs degrading marine bacterium Nah-1 and its degradative genePolycyclic aromatic hydrocarbons (PAHs) are a group of compounds composed of two or more fused aromatic rings widely spread in marine environment. It's accumulation in the environment has tremendous potential hazards on human health and ecological environment so environmental scientists have pay more and more attention to (PAHs).The sediment samples used in this study were collected from the MD05-2907 site(24°47.19'N,122°29.30'E) in the Southern Okinawa Trough at a depth of 1245 m in May 2005.A PAHs-degrading psychrophilic bacterium,with naphthalene as sole carbon and energy source, was isolated from deep-sea sediment of Southern Okinawa Trough.The growth curve of this bacterium was determined and the optimum growth conditions of this bacterium were studied. This study provided microbial resources for the biodegradation of marine polycyclic aromatic hydrocarbons ( PAHs) .Cell morphology and flagellation were examined and was a gram-negative.Under the optimum conditions of 16℃, salinity level of 30‰,naphthalene mass concentration 500 mg/L,the degradation of naphthalene is completely in 72 h.16S rDNA sequences analysis indicated that it belongs to the genus Cycloclasticus. The aligned sequences were imported into the 16SrDNA sequence Cycloclasticus spirillensus P1(GenBanK accession no.:DQ659429)A fragment of the degrading dioxygenase gene was obtained through PCR from Nah-1. And sequence alignment revealed that it was similar to the phnA1 gene of Cycloclasticus sp. A5(GenBanK accession no.:AB102786), which encoded a putative naphthalene dioxygenase large subunit.