title: Enhanced Alcaligenes faecalis Denitrification Rate with Electrodes as the Electron Donor.
abstract: The utilization by Alcaligenes faecalis of electrodes as the electron donor for denitrification was investigated in this study. The denitrification rate of A. faecalis with a poised potential was greatly enhanced compared with that of the controls without poised potentials. For nitrate reduction, although A. faecalis could not reduce nitrate, at three poised potentials of +0.06, -0.06, and -0.15 V (versus normal hydrogen electrode [NHE]), the nitrate was partially reduced with -0.15- and -0.06-V potentials at rates of 17.3 and 28.5 mg/liter/day, respectively. The percentages of reduction for -0.15 and -0.06 V were 52.4 and 30.4%, respectively. Meanwhile, for nitrite reduction, the poised potentials greatly enhanced the nitrite reduction. The nitrite reduction rates for three poised potentials (-0.06, -0.15, and -0.30 V) were 1.98, 4.37, and 3.91 mg/liter/h, respectively. When the potentials were cut off, the nitrite reduction rate was maintained for 1.5 h (from 2.3 to 2.25 mg/liter/h) and then greatly decreased, and the reduction rate (0.38 mg/liter/h) was about 1/6 compared with the rate (2.3 mg/liter/h) when potential was on. Then the potentials resumed, but the reduction rate did not resume and was only 2 times higher than the rate when the potential was off.
authors.affiliation: The Key Laboratory of Orogenic Belts and Crustal Evolution, School of Earth and Space Sciences, Peking University, Beijing, China.
authors.forename: Xin
authors.initials: X
authors.lastname: Wang
authors.affiliation: China Goldgroup Resources Co., Ltd., Beijing, China.
authors.forename: Ping
authors.initials: P
authors.lastname: Yu
authors.affiliation: The Key Laboratory of Orogenic Belts and Crustal Evolution, School of Earth and Space Sciences, Peking University, Beijing, China.
authors.forename: Cuiping
authors.initials: C
authors.lastname: Zeng
authors.affiliation: The Key Laboratory of Orogenic Belts and Crustal Evolution, School of Earth and Space Sciences, Peking University, Beijing, China.
authors.forename: Hongrui
authors.initials: H
authors.lastname: Ding
authors.affiliation: The Key Laboratory of Orogenic Belts and Crustal Evolution, School of Earth and Space Sciences, Peking University, Beijing, China liyan-pku@163.com ahlu@pku.edu.cn.
authors.forename: Yan
authors.initials: Y
authors.lastname: Li
authors.affiliation: The Key Laboratory of Orogenic Belts and Crustal Evolution, School of Earth and Space Sciences, Peking University, Beijing, China.
authors.forename: Changqiu
authors.initials: C
authors.lastname: Wang
authors.affiliation: The Key Laboratory of Orogenic Belts and Crustal Evolution, School of Earth and Space Sciences, Peking University, Beijing, China liyan-pku@163.com ahlu@pku.edu.cn.
authors.forename: Anhuai
authors.initials: A
authors.lastname: Lu
mesh_terms: D042481:Alcaligenes faecalis / Q000378:metabolism*; D058440:Denitrification; D004566:Electrodes / Q000382:microbiology*; D004579:Electron Transport; D009566:Nitrates / Q000378:metabolism; D009573:Nitrites / Q000378:metabolism; D010084:Oxidation-Reduction
chemical_list: D009566:Nitrates; D009573:Nitrites