title: Effects of cathode potentials and nitrate concentrations on dissimilatory nitrate reductions by Pseudomonas alcaliphila in bioelectrochemical systems.
abstract: The effects of cathode potentials and initial nitrate concentrations on nitrate reduction in bioelectrochemical systems (BESs) were reported. These factors could partition nitrate reduction between denitrification and dissimilatory nitrate reduction to ammonium (DNRA). Pseudomonas alcaliphilastrain MBR utilized an electrode as the sole electron donor and nitrate as the sole electron acceptor. When the cathode potential was set from -0.3 to -1.1 V (vs. Ag/AgCl) at an initial nitrate concentration of 100 mg NO3(-)-N/L, the DNRA electron recovery increased from (10.76 ± 1.6)% to (35.06 ± 0.99)%; the denitrification electron recovery decreased from (63.42 ± 1.32)% to (44.33 ± 1.92)%. When the initial nitrate concentration increased from (29.09 ± 0.24) to (490.97 ± 3.49) mg NO3(-)-N/L at the same potential (-0.9 V), denitrification electron recovery increased from (5.88 ± 1.08)% to (50.19 ± 2.59)%; the DNRA electron recovery declined from (48.79 ± 1.32)% to (16.02 ± 1.41)%. The prevalence of DNRA occurred at high ratios of electron donors to acceptors in the BESs and denitrification prevailed against DNRA under a lower ratio of electron donors to acceptors. These results had a potential application value of regulating the transformation of nitrate to N2 or ammonium in BESs for nitrate removal.
authors: College of Life Sciences, Sichuan University, Chengdu 610064, China; Key Laboratory of Environmental and Applied Microbiology, Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu 610041, China. Electronic address: wenjiezhang1986@gmail.com.
authors: Wenjie
authors: W
authors: Zhang
authors: Key Laboratory of Environmental and Applied Microbiology, Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu 610041, China; Environmental Microbiology Key Laboratory of Sichuan Province, Chengdu 610041, China.
authors: Yao
authors: Y
authors: Zhang
authors: Key Laboratory of Environmental and Applied Microbiology, Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu 610041, China; Environmental Microbiology Key Laboratory of Sichuan Province, Chengdu 610041, China.
authors: Wentao
authors: W
authors: Su
authors: Key Laboratory of Environmental and Applied Microbiology, Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu 610041, China; Environmental Microbiology Key Laboratory of Sichuan Province, Chengdu 610041, China.
authors: Yong
authors: Y
authors: Jiang
authors: College of Life Sciences, Sichuan University, Chengdu 610064, China; Key Laboratory of Environmental and Applied Microbiology, Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu 610041, China.
authors: Min
authors: M
authors: Su
authors: College of Life Sciences, Sichuan University, Chengdu 610064, China.
authors: Ping
authors: P
authors: Gao
authors: Key Laboratory of Environmental and Applied Microbiology, Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu 610041, China; Environmental Microbiology Key Laboratory of Sichuan Province, Chengdu 610041, China. Electronic address: gaoping99@hotmail.com.
authors: Daping
authors: D
authors: Li
mesh_terms: D001674:Bioelectric Energy Sources; D058440:Denitrification; D004566:Electrodes; D009566:Nitrates / Q000378:metabolism; D010084:Oxidation-Reduction; D011549:Pseudomonas / Q000378:metabolism*
chemical_list: D009566:Nitrates
keywords: Pseudomonas alcaliphila MBR; bioelectrochemical systems; cathode potential; denitrification; dissimilatory nitrate reduction