The bacterial communities of bioelectrochemical systems associated with the sulfate removal under different pHs

•Pyrosequencing reveals how pH affected BES sulfate removal with the change of bacterial community.•Phylotype richness and phylogenetic diversity are positively correlated pH in the BESs.•D. butyrativorans, D. marrakechensis and Desulfomicrobium sp. might enhance the sulfate removal.•Desulfomicrobium contributes to sulfate removal in pH 8.5, so does Desulfovibrio in pH 4.5 and 6.5.•Sulfuricurvum weakened sulfate removal in pH 8.5, so does Thiomonas in pH 4.5 and 6.5.