Microbial communities in an anaerobic dynamic membrane bioreactor (AnDMBR) for municipal wastewater treatment: Comparison of bulk sludge and cake layer

► Pyrosequencing reveals high microbial diversity in the bulk sludge and cake layer. ► Colonizers of the cake layer were mainly originated from the bulk sludge. ► Microbial evolution occurred due to the selective pressure and environmental stress. ► Bacteroides, Clostridia and δ-proteobacteria were the pioneers of colonization on membranes.