中文摘要：

研究首次于珠江口沉积物中分离出多株好氧反硝化细菌，从中筛选出一株反硝化性能最强的菌株A14-1。综合其生理生化及分子生物学鉴定的结果确定此曲株为红球菌属Rhodococcus aetherivorar。此菌株可在48h内将培养基中的硝酸盐含量从157．91mg·L-1降低至32．07mg·L-1，反硝化效率高达26．20mg·L-1·h-1，且不会产生亚硝酸盐的明显积累。以细菌总基因组DNA为模板成功扩增出亚硝酸还原酶基因nirS，说明亚硝酸还原酶可能参与了此菌株的好氧反硝化过程，将亚硝酸盐进一步还原，从而不会造成水体亚硝酸盐的积累。菌株A14-1在珠江口多个站点均有分布，环境适应能力强，且不会对环境造成危害，因此有望应用于污水的生物脱氮处理中。

英文摘要：

Several aerobic denitrifiers were isolated for the first time from sediments of the Pearl River Estuary, and strain A14-1 with the highest nitrogen removal rate was selected. The strain was identified as Rhodococcus aetherivorar according to physiological and biochemical characteristics and sequence analysis of 16S rDNA. It has a denitrification efficiency up to 26.20 mg·L-1.h1, being able to reduce the nitrate concentration of medium from 157.91 mgoLl to 32.07 mgoL1 in 48 h. The aerobic denitrification process showed no accumulation of nitrite, indicating the presence of nitrite reductase, which was verified by the nitrite reductase functional gene nitS through amplification. Strain A14-1 was expected to be used in wastewater nitrogen removal, considering its good adaptability and harmlessness to the environment.