title: Linkages between microbial functional potential and wastewater constituents in large-scale membrane bioreactors for municipal wastewater treatment.
abstract: Large-scale membrane bioreactors (MBRs) have been widely used for the municipal wastewater treatment, whose performance relies on microbial communities of activated sludge. Nevertheless, microbial functional structures in MBRs remain little understood. To gain insight into functional genes and their steering environmental factors, we adopted GeoChip, a high-throughput microarray-based tool, to examine microbial genes in four large-scale, in-operation MBRs located in Beijing, China. The results revealed substantial microbial gene heterogeneity (43.7-85.1% overlaps) among different MBRs. Mantel tests indicated that microbial nutrient cycling genes were significantly (P < 0.05) correlated to influent COD, [Formula: see text] -N, TP or sulfate, which signified the importance of microbial mediation of wastewater constituent removal. In addition, functional genes shared by all four MBRs contained a large number of genes involved in antibiotics resistance, metal resistance and organic remediation, suggesting that they were required for degradation or resistance to toxic compounds in wastewater. The linkages between microbial functional structures and environmental variables were also unveiled by the finding of hydraulic retention time, influent COD, [Formula: see text] -N, mixed liquid temperature and humic substances as major factors shaping microbial communities. Together, the results presented demonstrate the utility of GeoChip-based microarray approach in examining microbial communities of wastewater treatment plants and provide insights into the forces driving important processes of element cycling.
authors.affiliation: State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing 100084, PR China.
authors.forename: Yanmei
authors.initials: Y
authors.lastname: Sun
authors.affiliation: State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing 100084, PR China.
authors.forename: Yue-xiao
authors.initials: YX
authors.lastname: Shen
authors.affiliation: State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing 100084, PR China.
authors.forename: Peng
authors.initials: P
authors.lastname: Liang
authors.affiliation: State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing 100084, PR China; Institute for Environmental Genomics, Department of Botany and Microbiology, University of Oklahoma, Norman, OK 73019, USA; Earth Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA.
authors.forename: Jizhong
authors.initials: J
authors.lastname: Zhou
authors.affiliation: State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing 100084, PR China. Electronic address: yangyf@tsinghua.edu.cn.
authors.forename: Yunfeng
authors.initials: Y
authors.lastname: Yang
authors.affiliation: State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing 100084, PR China. Electronic address: xhuang@tsinghua.edu.cn.
authors.forename: Xia
authors.initials: X
authors.lastname: Huang
mesh_terms: D001419:Bacteria / Q000378:metabolism*; D001426:Bacterial Proteins / Q000378:metabolism; D019149:Bioreactors; D002947:Cities; D015964:Gene Expression Regulation, Bacterial / Q000502:physiology; D008567:Membranes, Artificial; D014865:Waste Disposal, Fluid / Q000379:methods*; D062065:Wastewater / Q000382:microbiology*; D014873:Water Pollutants
chemical_list: D001426:Bacterial Proteins; D008567:Membranes, Artificial; D062065:Wastewater; D014873:Water Pollutants
keywords: Functional genes; GeoChip; Membrane bioreactor; Municipal wastewater