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Nitrogen-removal efficiency of a novel aerobic denitrifying bacterium, Pseudomonas stutzeri strain ZF31, isolated from a drinking-water reservoir

Huang, Tinglin, Guo, Lin, Zhang, Haihan, Su, Junfeng, Wen, Gang, Zhang, Kai
Bioresource technology 2015 v.196 pp. 209-216
Pseudomonas stutzeri, bioremediation, carbon nitrogen ratio, denitrification, denitrifying bacteria, drinking water, genes, nitrate nitrogen, nitrites, nitrogen, nitrogen balance, pH, response surface methodology, temperature
An aerobic denitrifier, identified as Pseudomonas stutzeri strain ZF31, was isolated from the Zhoucun drinking-water reservoir. Strain ZF31 removed 97% of nitrate nitrogen after 16h, without nitrite accumulation. Sequence amplification indicated the presence of the denitrification genes napA, nirS, norB, and nosZ. Nitrogen balance analysis revealed that approximately 75% of the initial nitrogen was removed as gas products. Response surface methodology (RSM) experiments showed that maximum removal of total nitrogen (TN) occurred at pH 8.23, a C/N ratio of 6.68, temperature of 27.72°C, and with shaking at 54.15rpm. The TN removal rate at low C/N ratio (i.e., 3) and low temperature (i.e., 10°C) was 73.30% and 60.08%, respectively. These results suggest that strain ZF31 has potential applications for the bioremediation of slightly polluted drinking-water reservoirs.