Identification and phylogenetic analysis of an isolated denitrifier from rotating drum biofilter

A heterotrophic denitrifying strain named ND1 has been isolated from rotating drum biofilter(RDB) which was mainly used for the treatment of exhaust gas such as NOx.It was proved to be Gram-negative.In addition,it was able to form dry and wrinkled colonies on the medium,adhere on the agar surface,produce yellow pigments and be motile with a single polar flagellum.It was indentified as the Pseudomonas stutzeri according to morphological and physiological biochemical characteristics and 16S rDNA sequence analysis.Under the conditions of pH 7.2 and temperature 30℃,the NO 3--N removal efficiency by ND1 was up to 100% in 5 days,while the NO 2--N degradation ratio was only 85% by the strain DN1 when subjected to the same condition as the above.