title: Diversity and degradation mechanism of an anaerobic bacterial community treating phenolic wastewater with sulfate as an electron acceptor.
abstract: Petrochemical wastewater often contains high concentrations of phenol and sulfate that must be properly treated to meet discharge standards. This study acclimated anaerobic-activated sludge to treat saline phenolic wastewater with sulfate reduction and clarified the diversity and degradation mechanism of the microbial community. The active sludge in an upflow anaerobic sludge blanket (UASB) reactor could remove 90 % of phenol and maintain the effluent concentration of SO4 (2-) below 400 mg/L. Cloning and sequencing showed that Clostridium spp. and Desulfotomaculum spp. were major phenol-degrading bacteria. Phenol was probably degraded through the carboxylation pathway and sulfate reduction catalyzed by adenosine-5'-phosphosulfate (APS) reductase and dissimilatory sulfite reductase (DSR). A real-time polymerase chain reaction (RT-PCR) showed that as phenol concentration increased, the quantities of 16S rRNA gene, dsrB, and mcrA in the sludge all decreased. The relative abundance of dsrB dropped to 12.46 %, while that of mcrA increased to 56.18 %. The change in the electron flow ratio suggested that the chemical oxygen demand (COD) was removed mainly by sulfate-reducing bacteria under a phenol concentration of 420 mg/L, whereas it was removed mainly by methanogens above 630 mg/L.
authors.affiliation: State Environmental Protection Key Laboratory of Environmental Risk Assessment and Control on Chemical Process, State Key Laboratory of Biological Reactor Engineering, School of Resource and Environmental Engineering, East China University of Science and Technology, Shanghai, 200237, People's Republic of China.
authors.forename: X J
authors.initials: XJ
authors.lastname: Guo
authors.affiliation: State Environmental Protection Key Laboratory of Environmental Risk Assessment and Control on Chemical Process, State Key Laboratory of Biological Reactor Engineering, School of Resource and Environmental Engineering, East China University of Science and Technology, Shanghai, 200237, People's Republic of China.
authors.forename: Z Y
authors.initials: ZY
authors.lastname: Lu
authors.affiliation: School of Bioengineering, East China University of Science and Technology, Shanghai, 200237, People's Republic of China.
authors.forename: P
authors.initials: P
authors.lastname: Wang
authors.affiliation: State Environmental Protection Key Laboratory of Environmental Risk Assessment and Control on Chemical Process, State Key Laboratory of Biological Reactor Engineering, School of Resource and Environmental Engineering, East China University of Science and Technology, Shanghai, 200237, People's Republic of China. huili@ecust.edu.cn.
authors.forename: H
authors.initials: H
authors.lastname: Li
authors.affiliation: State Environmental Protection Key Laboratory of Environmental Risk Assessment and Control on Chemical Process, State Key Laboratory of Biological Reactor Engineering, School of Resource and Environmental Engineering, East China University of Science and Technology, Shanghai, 200237, People's Republic of China.|School of Chemical Engineering, Shanghai University of Engineering Science, Shanghai, 201620, People's Republic of China.
authors.forename: Z Z
authors.initials: ZZ
authors.lastname: Huang
authors.affiliation: State Environmental Protection Key Laboratory of Environmental Risk Assessment and Control on Chemical Process, State Key Laboratory of Biological Reactor Engineering, School of Resource and Environmental Engineering, East China University of Science and Technology, Shanghai, 200237, People's Republic of China.
authors.forename: K F
authors.initials: KF
authors.lastname: Lin
authors.affiliation: State Environmental Protection Key Laboratory of Environmental Risk Assessment and Control on Chemical Process, State Key Laboratory of Biological Reactor Engineering, School of Resource and Environmental Engineering, East China University of Science and Technology, Shanghai, 200237, People's Republic of China. ydliu@ecust.edu.cn.
authors.forename: Y D
authors.initials: YD
authors.lastname: Liu
mesh_terms: D019149:Bioreactors / Q000382:microbiology; D003013:Clostridium / Q000378:metabolism; D045859:Desulfotomaculum / Q000378:metabolism; D004583:Electrons; D059013:Microbial Consortia; D016877:Oxidants; D019800:Phenol / Q000378:metabolism*; D012336:RNA, Ribosomal, 16S / Q000235:genetics*; D060888:Real-Time Polymerase Chain Reaction; D012722:Sewage / Q000382:microbiology*; D013431:Sulfates / Q000378:metabolism*; D014865:Waste Disposal, Fluid; D062065:Wastewater
chemical_list: D016877:Oxidants; D019800:Phenol; D012336:RNA, Ribosomal, 16S; D012722:Sewage; D013431:Sulfates; D062065:Wastewater
keywords: Anaerobic treatment; Bacterial community; Degradation mechanism; High sulfate concentration; Phenolic wastewater; Real-time PCR