Rapid Enrichment and Cultivation of Denitrifying Phosphate-Removal Bacteria and Its Identification by Fluorescence in situ Hybridization Technology

The present work focused on a rapid enrichment and cultivation of denitrifying phosphate-removal bacteria(DPB) in a membrane bio-reactor(MBR) by using A2/ O anaerobic sludge from a wastewater treatment plant as seed,as well as providing an identification method.In the experiments,sodium acetate was used as the carbon source and a certain amount of nitrate was added to the MBR in the anoxic stage.Results showed that,with the efficient trap of the hollow-fiber membrane module,the proportion of DPB in all the phosphate-accumulating organisms(PAOs) increased from 24% to 93% within 35 days after two-stage's cultivation including anaerobic / aerobic and anaerobic / anoxic,during which the removal efficiency of nitrogen and phosphorus reached more than 90%.The activated sludge was identified by combining a regular method and the fluorescence in situ hybridization(FISH) technique,which demonstrated that Pseudomonas sp.and Rhodocyclus sp.were the dominant bacteria in the used bioreactor.