Biological nitrogen and phosphorus removal by a phosphorus-accumulating bacteria Acinetobacter sp. strain C-13 with the ability of heterotrophic nitrification-aerobic denitrification

Strain C-13, identified as an Acinetobacter sp. by homology searches, exhibited efficient simultaneous hetemtrophic nitrification-aerobic denitrification phosphorus removal (SNDPR) abilities by nitrogen balance analysis and further confirmation of successful amplification of functional genes ppk, napA, and nirS. In addition, strain C-13 could utilize NH4-N, NO3-, and NO2--N as nitrogen sources, among which NH4-N was indicated to be an excellent nitrogen source for assimilation and heterotrophic nitrification. Besides, the optimum conditions for nutrient removal were determined as follows: sodium acetate as the sole carbon source, C/N/P ratio of 100/10/2, pH = 7.5, and temperature of 30 degrees C. Meanwhile, the strain also showed the traditional features, such as release and the excess uptake of phosphate under anaerobic/aerobic conditions, with the highest phosphorus content of 5.01% after cultivation. Strain C-13 presents promising prospects for application in biological nutrient removal in wastewater treatment.

Automated summary

Strain C-13, identified as Acinetobacter sp., showed efficient simultaneous heterotrophic nitrification-aerobic denitrification and phosphorus removal abilities. It could utilize various nitrogen sources and had promising prospects for biological nutrient removal in wastewater treatment under optimum conditions. Additionally, C-13 exhibited traditional features of releasing and excess uptake of phosphate under anaerobic/aerobic conditions.