title: Selenate and Nitrate Bioreductions Using Methane as the Electron Donor in a Membrane Biofilm Reactor.
abstract: Selenate (SeO4(2-)) bioreduction is possible with oxidation of a range of organic or inorganic electron donors, but it never has been reported with methane gas (CH4) as the electron donor. In this study, we achieved complete SeO4(2-) bioreduction in a membrane biofilm reactor (MBfR) using CH4 as the sole added electron donor. The introduction of nitrate (NO3(-)) slightly inhibited SeO4(2-) reduction, but the two oxyanions were simultaneously reduced, even when the supply rate of CH4 was limited. The main SeO4(2-)-reduction product was nanospherical Se(0), which was identified by scanning electron microscopy coupled to energy dispersive X-ray analysis (SEM-EDS). Community analysis provided evidence for two mechanisms for SeO4(2-) bioreduction in the CH4-based MBfR: a single methanotrophic genus, such as Methylomonas, performed CH4 oxidation directly coupled to SeO4(2-) reduction, and a methanotroph oxidized CH4 to form organic metabolites that were electron donors for a synergistic SeO4(2-)-reducing bacterium.
authors: Department of Environmental Engineering, College of Environmental and Resource Science, Zhejiang University , Hangzhou, China.|Ministry of Education Key Laboratory of Environmental Remediation and Ecological Health, College of Environmental and Resource Sciences, Zhejiang University , Hangzhou 310058, China.|Zhejiang Province Key Lab Water Pollut Control & Envi, Zhejiang University , Hangzhou, Zhejiang China.
authors: Chun-Yu
authors: CY
authors: Lai
authors: Department of Environmental Engineering, College of Environmental and Resource Science, Zhejiang University , Hangzhou, China.
authors: Li-Lian
authors: LL
authors: Wen
authors: Department of Environmental Engineering, College of Environmental and Resource Science, Zhejiang University , Hangzhou, China.
authors: Ling-Dong
authors: LD
authors: Shi
authors: Department of Environmental Engineering, College of Environmental and Resource Science, Zhejiang University , Hangzhou, China.
authors: Kan-Kan
authors: KK
authors: Zhao
authors: Department of Environmental Engineering, College of Environmental and Resource Science, Zhejiang University , Hangzhou, China.
authors: Yi-Qi
authors: YQ
authors: Wang
authors: Ministry of Education Key Laboratory of Environmental Remediation and Ecological Health, College of Environmental and Resource Sciences, Zhejiang University , Hangzhou 310058, China.
authors: Xiaoe
authors: X
authors: Yang
authors: Swette Center for Environmental Biotechnology, Biodesign Institute at Arizona State University , P.O. Box 875701, Tempe, Arizona 85287-5701, United States.
authors: Bruce E
authors: BE
authors: Rittmann
authors: Swette Center for Environmental Biotechnology, Biodesign Institute at Arizona State University , P.O. Box 875701, Tempe, Arizona 85287-5701, United States.
authors: Chen
authors: C
authors: Zhou
authors: Department of Civil and Environmental Engineering, FAMU-FSU College of Engineering, Florida State University , Tallahassee, Florida 32310-6046, United States.
authors: Youneng
authors: Y
authors: Tang
authors: Department of Environmental Engineering, College of Environmental and Resource Science, Zhejiang University , Hangzhou, China.|Zhejiang Province Key Lab Water Pollut Control & Envi, Zhejiang University , Hangzhou, Zhejiang China.
authors: Ping
authors: P
authors: Zheng
authors: Department of Environmental Engineering, College of Environmental and Resource Science, Zhejiang University , Hangzhou, China.|Zhejiang Province Key Lab Water Pollut Control & Envi, Zhejiang University , Hangzhou, Zhejiang China.
authors: He-Ping
authors: HP
authors: Zhao
mesh_terms: D018441:Biofilms; D019149:Bioreactors; D008697:Methane / Q000378:metabolism*; D010084:Oxidation-Reduction; D064586:Selenic Acid
chemical_list: D064586:Selenic Acid; D008697:Methane