A newly isolated and rapid denitrifier Pseudomonas citronellolis WXP-4: difference in N2O emissions under aerobic and anaerobic conditions

• Published in: Bioprocess and biosystems engineering Vol. 43; no. 5; pp. 811 - 820
• Main Authors: Wang, Xiaoping, Duo, Yankai, He, Jinjia, Yao, Jiachao, Qian, Haifeng, Hrynsphan, Dzmitry, Tatsiana, Savitskaya, Chen, Jun
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 01.05.2020; Springer Nature B.V
• Subjects: Aerobic conditions; Anaerobic conditions; Anaerobic processes; Bacteria; Biotechnology; carbon; Carbon sources; Carbon/nitrogen ratio; Chemistry; Chemistry and Materials Science; denitrification; denitrifying bacteria; Emissions; Environmental Engineering/Biotechnology; Fluorescence; Food Science; genes; greenhouse gas emissions; Industrial and Production Engineering; Industrial Chemistry/Chemical Engineering; nitrate nitrogen; Nitrates; nitrites; nitrogen; Nitrogen removal; Nitrous oxide; nitrous-oxide reductase; NorB protein; Pseudomonas; Pseudomonas citronellolis; quantitative polymerase chain reaction; Reductase; Reductases; Relative abundance; Research Paper; Sodium succinate; Strain analysis; succinic acid; temperature; Wastewater treatment; Nitrogen removal; Metabolic pathway; Denitrification genes; Nitrous oxide; Fluorescence quantitative PCR
• ISSN: 1615-7591; 1615-7605; 1615-7605
• DOI: 10.1007/s00449-019-02276-6

A novel and efficient facultative anaerobic denitrifying bacterium was isolated and identified as Pseudomonas citronellolis WXP-4. The strain WXP-4 could achieve 100% nitrate and nitrite removal efficiency utilizing sodium succinate as a carbon source, C/N ratio 7, pH 7.0, and temperature 40 °C under both aerobic and anaerobic conditions. The bacterium could tolerate a wide range of NO 3 − –N concentrations from 100 to 1000 mg/L with a maximum nitrogen removal rate of 32.05 mg/(L h). An interesting phenomenon was found that no N 2 O emission occurred during the denitrifying process under anaerobic conditions, while there was 0.06 mg/L under aerobic conditions. This phenomenon had been confirmed by fluorescence quantitative PCR and the results showed that the relative abundance of nosZ gene increased by 17-fold based on the ratio of anaerobic to aerobic, and thus, nosZ gene could encode more nitrous oxide reductase to accelerate the conversion of N 2 O under anaerobic conditions. Moreover, the narG , nirK, and norB genes were also identified in the denitrifying pathway of the strain WXP-4. This investigation has demonstrated enormous potential for the future application in wastewater treatment systems. Graphic abstract