title: Metabolic properties of a mixed culture of aerobic ammonia oxidizers and its optimal reaction conditions.
abstract: The aerobic ammonia oxidation is an important process for nitrogen removal from wastewater with high ammonia concentration. Here, we investigated the metabolic properties of a mixed culture of aerobic ammonia oxidizers and determined its optimal reaction conditions. The maximum specific rate of NO(2)(-)-N formation of the culture was 14.9 mg N mg(protein)(-1) d(-1). The ammonia oxidation capacity was positively correlated with the microbial biomass concentration. Haldane model showed that the half-saturation constant (K(s)) for NH(4)(+)-N of the culture was 78.5 mg L(-1), and the inhibition constant (K(i)) for NH(4)(+)-N was 393.4 mg L(-1). The acetic acid and beef extract had significant inhibitory effects on ammonia oxidation, while there was little effect of methanol and glucose on ammonia oxidation. Orthogonal experiments with range analysis, variance analysis, factor contribution analysis and response surface analysis confirmed the optimal reaction conditions for ammonia oxidation to be 30-32 °C, pH 7.8-8.0, and 150-200 mg L(-1) NH(4)(+)-N concentration.
authors.affiliation: Department of Environmental Engineering, Zhejiang University, Hangzhou 310058, China.
authors.forename: Li-dong
authors.initials: LD
authors.lastname: Shen
authors.forename: Peng
authors.initials: P
authors.lastname: Chen
authors.forename: Fan-zhong
authors.initials: FZ
authors.lastname: He
authors.forename: An-hui
authors.initials: AH
authors.lastname: Hu
authors.forename: Ping
authors.initials: P
authors.lastname: Zheng
authors.forename: Xiang-yang
authors.initials: XY
authors.lastname: Xu
authors.forename: Bao-lan
authors.initials: BL
authors.lastname: Hu
mesh_terms: D000641:Ammonia / Q000378:metabolism*; D001420:Bacteria, Aerobic / Q000145:classification* / Q000378:metabolism*; D019149:Bioreactors / Q000382:microbiology*; D018929:Cell Culture Techniques / Q000379:methods; D003198:Computer Simulation; D003470:Culture Media / Q000378:metabolism*; D008954:Models, Biological; D010084:Oxidation-Reduction; D010100:Oxygen / Q000378:metabolism*; D013045:Species Specificity
chemical_list: D003470:Culture Media; D000641:Ammonia; D010100:Oxygen