Diversity Of Bacterial Communities In Coastal Areas Of Shandong Province

Marine bacteria play a key role in production and degradation of organic matters, the bioremediation in marine environments, as well as the energy flow and nutrients cycling. To investigate diversity and composition of bacterial communities, sampling were carried out in coastal areas of Shandong province during August of 2006(summer), April of 2007(spring) and October of 2007(autumn) using ARDRA. 16S rDNA fragments of bacteria were PCR amplified and 16S rDNA clone libraries were constructed to investigate bacterial diversity and community composition.At station SD1, the numbers of positives which have different enzyme digestion maps were 45,30, and 51 respectively. The coverage of the three libraries were 77.5%, 85.0% and 74.5% respectively. At the same time, in the station SD2, the numbers of positives which have different enzyme digestion maps were 42,47 and 41 respectively. The coverage of the three libraries were 79.0%,76.5% and 79.5% respectively. The coverage of the two stations' libraries were all above 70%, so these libraries can reflect the bacterial diversity in the marine environment.Diversity of bacterial community was higher at station SD2 than SD1. Four main lineages, Proteobacteria, Cyanobacteria, Bacteroidetes and Planctomycetes, were investigated at SD1,.compared with the published sequences in GenBank database and guided by the phylogenetic tree. a-Proteobacteria dominated the community at SD1,, followed by Cyanobacteria and Bacteroidetes. Eight main lineages, Proteobacteria, Actinobacteria, Bacteroidetes, Cyanobacteria, Verrucomicrobia, Acidobacteria, Firmicutes and Planctomycetes, were detected at station SD2. a-Proteobacteria dominated the community at station SD2, followed by y-Proteobacteria andε-Proteobacteria.The comparative analysis of bacterial diversity and the percentage of bacteria populations in the two station was made. The results showed that both the population composition and population quantity of the dominated bacterium varied slightly by season in the station SD1 and station SD2.Unknown species were detected at two stations, indicated that there were still many unknown new species in the marine in Shandong coast line.