Spatial heterogeneity of bacterial community structure in the sediments of the Pearl River estuary

Denaturing gradient gel electrophoresis (DGGE) and multivariate statistical analytical methods were applied to investigate the spatial variation of bacterial community structure in the Pearl River estuary sediment and to address the relationship between microbial community composition and bottom water chemistry in ten different stations. Preliminary results of sequencing analysis of the excised DGGE bands suggested that α-Proteobacteria, γ-Proteobacteria, Acidobacteria and Actinobacteria were the dominant bacterial groups in the Pearl River estuary sediment. Results of multidimensional scaling analysis of these field data suggested that the composition of bacterial communities varied with sampling sites. Finally, canonical correspondence analysis of the data of environmental variables and bacterial community suggested that bacterial community structure was significantly influenced by the change of environmental variables (total phosphorus, nitrite, ammonium, dissolved oxygen, pH and salinity).