Phylogenetic analysis of bacterial community composition in sediments with organic contaminants from the Jiaojiang estuary in China

•We studied sediment bacteria diversity and organic pollutants in Jiaojiang estuary.•Bacterial communities were determined using 16S rRNA and phylogenetic analysis.•Proteobacteria were the dominant bacterial group.•There was no clear relationship between the pollutants and bacterial diversity.•Polycyclic aromatic hydrocarbons were negatively correlated with Chloroflexi.

The aim of this study was to investigate the bacterial community composition, the concentration of organic contaminants, and their relationship in the sediments of Jiaojiang estuary. Sediments were collected from seven stations and the environmental parameters were analyzed. The results showed that the site closest to the chemical industry zone was the most polluted. Bacterial communities were determined using 16S rRNA clone libraries and phylogenetic analysis. These results revealed that there were 13 known bacterial phyla in the sediments and that Proteobacteria were the dominant group. Using these data, we assessed the correlation between bacterial communities and organic contaminants using cluster, multidimensional scaling, and redundancy analyses. These showed that there was no simple relationship between organic contaminants and bacterial community diversity in the sediments, but polycyclic aromatic hydrocarbons were more influential than the other pollutants and negatively affected Chloroflexi.