Aerobic denitrification by Pseudomonas stutzeri C3 incapable of heterotrophic nitrification.

An aerobic denitrifier was isolated from activated sludge and the isolate possessed an average nitrate removal efficiency of 95.8% in 24 h, with the maximum nitrite accumulation of 25.6 mg/l. The bacterium could not conduct heterotrophic nitrification. The results of PCR indicated that the strain lacked the gene of amoA. The phylogenetic tree indicated a clear evolutionary divergence that Pseudomonas stutzeri C3 belonged to the group of strains that could not exhibit ammonia oxidation.