Study On Bacterial 16SrDNA Diversity In Southern Of PoYang Lake

PoYang Lake lies in the north of the JiXing province, which is the largest freshwarter lake in china. The PoYang Lake is divided into southern and northern parts by SongMong hill. The southern part of the lake is widely, which is the main lake. The northern part of the lake is long and narrow, which is a watercourse to the lake. Because of the unique geographical and climatic conditions, the PoYang Lake's microbial diversity is very rich.In this research, total DNA of bacterial were extracted directly from the samples NHI and NHII which come from the southern of PoYang Lake. Then using as template for polymerase chain reaction (PCR) amplification, which employ specific primwe for bacteria 16SrRNA gene suquences. The 16SrDNA libraries were then constructed. Microbial diversity of the southern of PoYang Lake were analyzed by Restriction Fragment Length Polymorphisma (RFLP), DNA sequencing and phylogenetic analysis.The results show that:(1 ) About the sample NHI, there are four phyla in bacteria domain: Proteobacteria,Actinobacteria,Verrucomicrobia,Bacteroidetes and 10 have not been determined the classification status . The Proteobacteria,Bacteroidetes and Actinobacteria are the predominant phyla, which respective shares of 47.2%,18.9% and 11.3%.(2) About the sample NHII, there are six phyla in bacteria domain: Proteobacteria,Actinobacteria,Cyanobacteria,Verrucomicrobia,Bacteroidetes,Planctomycetes and 8 have not been determined the classification status. The Proteobacteria,Bacteroidetes and Actinobacteria are the predominant phyla, which respective shares of 59.0%,9.8% and 8.2%.(3) Comparing in the GenBank database, more than 90% sequences come from 16SrDNA libraries similarity≥97%. This result indicated that the species of bacteria in southern of PoYang Lake are widely distributed and most of them have been found in other environmental samples. (4) The results of diversity Coverage C,Rarefaction curve,Shannon-Wiener index(H') and species richness (S_Chao1) calculated indicated that bacteria diversity are very rich.(5) Comparing the results of NHI and NHII we can find that the bacteria diversity of NHII is higher than NHI, which indicated that the bacteria diversity of southern of PoYang Lake are changing with seasons.(6) Results of this research compaired with the results of northern of PoYang Lake we can find that the bacteria diversity of southern of PoYang Lake is higher than northern of PoYang Lake.