title: Nitrogen removal by Providencia rettgeri strain YL with heterotrophic nitrification and aerobic denitrification.
abstract: Providencia rettgeri strain YL shows the capability of nitrogen removal under sole aerobic conditions. By using isotope ratio mass spectrometry, (15)N-labelled N2O and N2 were detected in aerobic batch cultures containing [Formula: see text], [Formula: see text] or [Formula: see text]. Strain YL converted [Formula: see text], [Formula: see text] and [Formula: see text] to produce more N2O than N2 in the presence of [Formula: see text]. An (15)N isotope tracing experiment confirmed that the nitrogen removal pathway of strain YL was heterotrophic nitrification-aerobic denitrification. The optimal treatment conditions for nitrogen removal were pH of 8, C/N ratio of 12, temperature of 25°C and shaking speed of 105 rpm. A continuous aerobic bioreactor inoculated with strain YL was developed. With an influent [Formula: see text] concentration of 90-200 mg/L, the [Formula: see text] removal efficiency ranged from 80% to 97% and the total nitrogen removal efficiency ranged from 72% to 95%. The nitrogen balance in the continuous bioreactor revealed that approximately 35-52% of influent [Formula: see text] was denitrified aerobically to form gaseous nitrogen. These findings show that the P. rettgeri strain YL has potential application in wastewater treatment for nitrogen removal under sole aerobic conditions.
authors.affiliation: a The Key Laboratory of Eco-environments in Three Gorges Reservoir Region , Chongqing University , Chongqing , People's Republic of China.
authors.forename: Jun
authors.initials: J
authors.lastname: Ye
authors.affiliation: a The Key Laboratory of Eco-environments in Three Gorges Reservoir Region , Chongqing University , Chongqing , People's Republic of China.
authors.forename: Bin
authors.initials: B
authors.lastname: Zhao
authors.affiliation: a The Key Laboratory of Eco-environments in Three Gorges Reservoir Region , Chongqing University , Chongqing , People's Republic of China.
authors.forename: Qiang
authors.initials: Q
authors.lastname: An
authors.affiliation: b National Centre for International Research of Low-carbon and Green Buildings , Chongqing University , Chongqing , People's Republic of China.
authors.forename: Yuan-Sheng
authors.initials: YS
authors.lastname: Huang
mesh_terms: D000332:Aerobiosis; D064751:Ammonium Compounds / Q000032:analysis / Q000378:metabolism; D019149:Bioreactors / Q000382:microbiology*; D058440:Denitrification; D052836:Heterotrophic Processes; D009584:Nitrogen / Q000032:analysis / Q000378:metabolism*; D009587:Nitrogen Isotopes / Q000032:analysis / Q000378:metabolism; D011532:Providencia / Q000378:metabolism*; D062065:Wastewater / Q000737:chemistry; D018508:Water Purification / Q000379:methods*
chemical_list: D064751:Ammonium Compounds; D009584:Nitrogen; D009587:Nitrogen Isotopes; D062065:Wastewater
keywords: Heterotrophic nitrification-aerobic denitrification; Providencia rettgeri; bioreactor; isotope tracing method; nitrogen removal