Abstract: In recent years, with the rapid development of China's aquaculture industry, factory intensive aquaculture has gradually become a trend in the development of China's aquaculture industry. In this high-density aquaculture model, the concentration of ammonia nitrogen, nitrite nitrogen, and nitrate nitrogen in the aquaculture water has become uncontrollable, the incidence of aquatic biological diseases has greatly increased, and the aquaculture environment has also been polluted, which has had a significant impact on the development of the aquaculture industry. At present, biological denitrification is considered as one of the most optimal strategies for treating aquaculture water, in which denitrifying bacteria play an irreplaceable role. This study screened a safe and efficient aerobic denitrifying bacterium from the sediment of aquaculture ponds, and classified and identified it as Ochrobactrum anthropi A14 through 16S rDNA sequence comparison. Safety testing was conducted, and with ammonia nitrogen, nitrite nitrogen, and nitrate nitrogen as the main indicators its denitrification performance was studied. The effects of different temperatures, pH, carbon sources, and C/N on the denitrification and denitrification of this strain were explored, as well as its application effect in water bodies. The strains isolated in this study have certain application value, and the research results have theoretical significance. The experimental results provide a feasible aspect for improving water pollution in aquaculture.

Key words: Ochrobactrum anthropi A14, aerobic denitrification, biological denitrification, water quality control