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Updated: Jun 26, 2026

Measurement of the Potential Rates of Dissimilatory Nitrate Reduction to Ammonium Based on 14NH4+/15NH4+ Analyses via Sequential Conversion to N2O
Published on: October 7, 2020
Aerobic denitrification of Pseudomonas putida AD-21 at different C/N ratios
Mia Kim1, Seong-Yun Jeong, Su Jeong Yoon
1Department of Microbiology, College of Natural Sciences, Pusan National University, Busan, Korea.
Abstract:
An aerobic denitrifier was newly isolated from soil and its denitrification activity under different C/N (carbon/nitrogen) ratios was investigated. The isolate was identified as Pseudomonas putida AD-21 by biochemical studies and 16s rDNA sequencing analysis. P. putida AD-21 tolerated oxygen levels of 5.0-6.0 mg/l. An (15)NH(4)/(14)NO(3) analysis indicated that the nitrogen of NH(4) was preferentially assimilated into the cell mass and that the nitrate removed could be considered an indication of bacterial denitrification efficiency. Increasing the C/N ratio increased the nitrate removal rates, whereas nitrogen assimilation into the cell mass was not affected. The optimal C/N ratio was 8 with a maximum nitrate removal rate of 254.6 mg/l/h and a nitrate removal efficiency of 95.9%. The results suggest that P. putida AD-21 may be a good candidate for aerobic wastewater treatment.
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