The bacterial diversity in surface sediments from Chongming Eastern tidal flat in summer and winter

Based on the total DNA extracted from the surface sediments of Chongming eastern tidal flat in the Yangtze estuary in summer and winter, the V3 area of 16S rRNA gene of bacteria were amplified. PCR products were cloned and sequenced, and 16S rRNA gene libraries were constructed. Phylogenetic analysis indicated that the bacteria in the surface sediments of Chongming eastern tidal flat fell into twelve known Phyla: Proteobacteria (α-, β-, γ-, δ-, ε-), Bacteroidetes, Actinobacteria, Acidobacteria, Chloroflexi, Firmicutes, Spirochaetes, Verrucomicrobia, Planctomycetes, Chlorobi, Dictyoglomi and Nitrospirae. Also, there were many sequences belonging to unidentified bacteria. Proteobacteria was the dominant group in the middle tidal flat and the low tidal flat, while Bacteroidetes was the dominant group in the high tidal flat. DOTUR analysis indicated that there were the most abundant species and highest bacterial community diversity in the middle tidal flat, followed by the low tidal flat, and the high tidal flat had the lowest bacterial community diversity. The bacterial community diversity was higher in summer than in winter. In comparison, the seasonal variation of bacterial communities in the sediment of the high tidal flat was the largest, and the variation in the middle tidal flat was the smallest.