Abstract:In order to screen strains with strong denitrification ability from different environments, the effects of carbon source, temperature, pH value, C/N, and uranium concentration on denitrification effect of strains were studied, and the growth curve of the strains was obtained under the optimal conditions. The results show that three highly efficient denitrifying bacteria were screened. When anhydrous sodium acetate is used as the best carbon source, the nitrate nitrogen removal rate of strain YWSY21 is 97.11%, and the nitrate nitrogen removal rate of strain 4 and 5 is more than 95% when sodium citrate is used as the best carbon source. Under the optimal conditions of temperature 26.31 ℃, pH=5.74 and C/N=12.95, the removal rate of nitrate nitrogen of Klebsiella variicola strain 21 is 90.77%. Under the optimal conditions of temperature 25.39 ℃, pH=5.90 and C/N=10.16, the removal rate of nitrate nitrogen of Pseudomonas nitroreducens strain 4is 89.27%.The removal rate of NO3--N by strain 5 is 85% above at 5 uranium concentrations. The growth curve of strain 4 under the optimal denitrification conditions exhibits high growth activity under the optimal growth conditions. It can provide bacteria source guarantee for bioremediation of nitrate wastewater from uranium mines.