Use of pyrosequencing to explore the benthic bacterial community structure in a river impacted by wastewater treatment plant discharges.

In this study, we determined the diversity and composition of benthic bacterial communities collected in river sediments upstream and downstream from a wastewater treatment plant (WWTP). Pyrosequencing of bacterial 16S rRNA genes revealed notable differences between the communities from upstream and downstream sites. In particular, a higher relative abundance of Acidobacteria, Chloroflexi, Deltaproteobacteria and Firmicutes and a lower proportion of Gammaproteobacteria and Verrucomicrobia sequences were detected at the downstream site compared to the upstream site. These findings represent a first approximation of the impact of WWTP discharges on environmental microbial communities.