Screening of nitrogen removal bacteria and its application in aquaculture wastewater treatment

In this study, a bacteria strain with strong nitrogen removal capability was isolated from the sediment of the aquaculture pond. Based on morphological observation and 16S rRNA gene sequence analysis, the strain was identified as Pseudomonas sp. and named Pseudomonas sp. DC1. The nitrogen removal performances of strain DC1 were evaluated using shake flasks method. When the strain DC1 was inoculated into simulated wastewater with ammonia nitrogen as the sole nitrogen source, the ammonia nitrogen concentration was decreased from 603.6mg/L to 58.55 mg/L within 24h, and the removal efficiency of ammonia nitrogen reached 90.3%. In the flask experiment with nitrate nitrogen as the sole nitrogen source, the removal efficiency of nitrate nitrogen reached 67.6% within 30h. Using strain DC1 to treat California perch aquaculture wastewater, the ammonia nitrogen concentration was decreased from 78.06 mg/L to 32.94 mg/L within 5 d, and the removal efficiency of ammonia nitrogen reached 57.3%. The above results revealed that strain DC1 is a new strain with strong nitrogen removal capability and could tolerate a high concentration of ammonia nitrogen, representing a great potential to treat aquaculture water and urban sewage.