Abstract:In this study, by switching operation mode from anaerobic / aerobic (A/O) to anaerobic / anoxic (A/An), we efficiently enriched denitrifying phosphorus removal bacteria (DPB) from PAOs, then we performed deformation gradient gel electrophoresis (DGGE) on 16S rRNA specific polymerase chain reaction (PCR) product and biodiversity analysis of these bacteria in five different acclimation phase (1#: sewage sludge; 2#~5#: the medium and latter phase of domestication). Our results indicated that the DPB was domesticated successfully by two-stage enrichment approach; Clostridium sp. and Beta proteobacterium bacteria can be isolated in the final stage. The former is Gram-positive and belongs to highly efficient phosphorus removal genus, while the latter is a Gram-negative, strictly polyphosphate anaerobic variant. We also detected a large number of unidentified bacteria strains, characteristics of which need further investigation.