Nitrogen removal characteristics of a heterotrophic nitrifier Acinetobacter junii YB and its potential application for the treatment of high-strength nitrogenous wastewater

• Published in: Bioresource technology 2015-10, Vol.193, p.227-233
• Main Authors: Yang, Lei, Ren, Yong-Xiang, Liang, Xian, Zhao, Si-Qi, Wang, Jun-ping, Xia, Zhi-Hong
• Format: Article
• Language: English
• Subjects: Acinetobacter - metabolism; Acinetobacter - physiology; Acinetobacter junii YB; Aerobiosis - physiology; Ammonium Compounds - metabolism; Denitrification - physiology; Heterotrophic nitrification–aerobic denitrification; Heterotrophic Processes - physiology; Hydrogen-Ion Concentration; Nitrates - metabolism; Nitrification - physiology; Nitrite removal; Nitrites - metabolism; Nitrogen - metabolism; Nitrogen removal mechanism; Oxygen - metabolism; Temperature; Waste Water - microbiology
• ISSN: 0960-8524; 1873-2976
• DOI: 10.1016/j.biortech.2015.05.075

•Strain YB possessed heterotrophic nitrification–aerobic denitrification ability.•Ammonium was found to be removed preferentially in mixed N-sources.•hao, napA and nirS genes were successfully expressed through PCR amplification.•High potential application of YB for the treatment of nitrogenous wastewater. Acinetobacter junii YB was found to exhibit efficient heterotrophic nitrification and aerobic denitrification ability, with the maximum ammonium, nitrite and nitrate removal rate of 8.82, 8.45 and 7.98mg/L/h, respectively. Meanwhile, ammonium was found to be removed preferentially in the process of simultaneous nitrification and denitrification in mixed N-sources. The successful PCR amplification of hao, napA and nirS genes further provided additional evidence of heterotrophic nitrification and aerobic denitrification by strain YB. In addition, orthogonal test showed that dissolved oxygen was the most important determinant of nitrite removal, and the optimal conditions were C/N 15, pH 7.0, 37°C and 200rpm. Furthermore, stable nitrogen and organics removal were achieved by one-time dosing of enriched bacteria in a sequencing batch reactor. The inoculation of strain YB significantly improved the denitrification efficiency with minimal accumulation of nitrified products, which demonstrated high potential of the isolate for future practical applications.