[Biological characteristics of denitrifying polyphosphate-accumulating organisms].

A denitrifying phosphate-accumulating organisms(DNPAOs),which was called Q-hrb05,was isolated in the special medium from the anaerobic/aerobic/anoxic SBR reactor.Strain Q-hrb05 was identified by 16SrDNA gene analysis,and the accession number of 16SrDNA gene sequence of strain Q-hrb05 in GenBank was GU214826.Effects of the different pH values,temperature,carbon source of medium on nitrogen and phosphorus removal of strain Q-hrb05 were investigated.The result showed that strain Q-hrb05 belonged to Bacillus sp..Meanwhile,extracellular exopolymers of strain Q-hrb05 was based on protein,about 120.6 mg·mL-1,and it had 23.05 μg·mL-1 nucleic acid,but little polysaccharide.There was no significant adsorption of phosphate.So phosphorus removal was mainly due to intracellular uptake.And when pH value was kept as 7,temperature was kept as 30℃,and carbon source was kept sodium acetate,the highest nitrogen and phosphorus removal efficiency was achieved.Phosphorus uptake rate was averaged at 88%,and the denitrification rate reached 81%.