Nitrogen accumulation is one of the major causes of water pollution and eutrophication in aquaculture. Excessive amounts of the toxic forms of nitrogen (ammonia and nitrite) have a considerable effect on the survival and growth of aquatic organisms and thus lead to huge economic loss in aquaculture. Biological nitrogen removal technology is an efficient process for nitrogen removal from water in aquatic habitats, wherein probiotic bacteria convert nitrite-N into nitrate nitrogen (nitrate-N) or nitrogen gas. Moreover, owing to lower energy consumption and operation cost, this technology is commonly used in aquaculture. Many studies have used several kinds of bacteria to reduce the toxic effects of nitrogen and demonstrated an improvement in water quality. The present study aimed to identify bacteria that efficiently removed nitrite nitrogen and ammonia nitrogen. The strain O-11 was isolated from shrimp culture water after enrichment culture and had removal efficiency for nitrite nitrogen and ammonia nitrogen of 96.17% and 88.27%, respectively, in 24 h. Molecular biological and physiological and biochemical identification revealed that the strain was closely related to . The isolated strain O-11removed nitrite nitrogen more efficiently when the temperature ranged from 20℃ to 30℃, while ammonia nitrogen removal was better when the temperature ranged from 20℃ to 35℃. The nitrite nitrogen removal ability of the isolated strain was stable when salinity was less than 30, while the ammonia nitrogen removal ability was considerably higher in alkaline conditions. A safety assessment revealed that the strain O-11 was safe for when the initial bacterial concentration ranged from 10⁵ to 10⁸ cfu/mL. The survival rate and growth rate of experimental significantly increased when the initial bacteria concentration was 10⁵ cfu/mL. These results demonstrated great potential value of the isolated strain O-11 as a suitable candidate for the removal of harmful forms of nitrogen from aquaculture water.