title: Denitrification characteristics of a marine origin psychrophilic aerobic denitrifying bacterium.
abstract: A psychrophilic aerobic denitrifying bacterium, strain S1-1, was isolated from a biological aerated filter conducted for treatment of recirculating water in a marine aquaculture system. Strain S1-1 was preliminarily identified as Psychrobacter sp. based on the analysis of its 16S rRNA gene sequence, which showed 100% sequence similarity to that of Psychrobacter sp. TSBY-70. Strain S1-1 grew well either in high nitrate or high nitrite conditions with a removal of 100% nitrate or 63.50% nitrite, and the total nitrogen removal rates could reach to 46.48% and 31.89%, respectively. The results indicated that nitrate was mainly reduced in its logarithmic growth phase with a very low level accumulation of nitrite, suggesting that the aerobic denitrification process of strain S1-1 occurred mainly in this phase. The GC-MS results showed that N2O was formed as the major intermediate during the aerobic denitrifying process of strain S1-1. Finally, factors affecting the growth of strain S1-1 and its aerobic denitrifying ability were also investigated. Results showed that the optimum aerobic denitrification conditions for strain S1-1 were sodium succinate as carbon source, C/N ratio15, salinity 10 g/L NaCl, incubation temperature 20 degrees C and initial pH 6.5.
authors.affiliation: State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China. zhenghaiyanzhy@126.com
authors.forename: Haiyan
authors.initials: H
authors.lastname: Zheng
authors.forename: Ying
authors.initials: Y
authors.lastname: Liu
authors.forename: Guangdong
authors.initials: G
authors.lastname: Sun
authors.forename: Xiyan
authors.initials: X
authors.lastname: Gao
authors.forename: Qingling
authors.initials: Q
authors.lastname: Zhang
authors.forename: Zhipei
authors.initials: Z
authors.lastname: Liu
mesh_terms: D000332:Aerobiosis; D017756:Aquaculture; D058440:Denitrification; D008401:Gas Chromatography-Mass Spectrometry; D006863:Hydrogen-Ion Concentration; D009573:Nitrites / Q000378:metabolism; D044096:Psychrobacter / Q000302:isolation & purification* / Q000378:metabolism*; D054712:Salinity; D013696:Temperature
chemical_list: D009573:Nitrites