Abstract: New types of aerobic denitrifying bacteria were isolated from the culture pond of the Xilang Pearl River Aquaculture Institute in Guangzhou,aiming at laying the foundation for the development of a new biological nitrogen removal process. Three different screening media were used to isolate the aerobic denitrifying bacteria,and the growth curve and denitrification performance of fermentation in a sole nitrogen source medium were determined. Then morphology and 16S rRNA gene sequence analysis were employed to identify the strains and a phylogenetic tree was constructed. As result,a high-performance aerobic denitrifying strain BB-17 was isolated. When the strain was cultured at 28℃,180 r/min in a sole nitrogen source medium,the logarithmic phase appeared at 6-24 h and the removal rate of ammonia nitrogen was up to 93.92% at 18 h,that of nitrate nitrogen reached 66.11% at 48 h,and that of nitrite nitrogen reached 99.10% at 48 h. BB-17 was a Gram-negative Brevibacterium,the results of 16S rDNA sequence analysis presented 98.41% homology with Pseudomonas vancouverensis（AJ011507）,and BB-17 was identified as Pseudomonas and named P. sp. BB17.

Key words: isolation, heterotrophic nitrification, aerobic denitrification, Pseudomonas