title: Effect of copper on the performance and bacterial communities of activated sludge using Illumina MiSeq platforms.
abstract: The anaerobic-anoxic-aerobic (A2O) process is a highly efficient sewage treatment method, which uses complex bacterial communities. However, the effect of copper on this process and the bacterial communities involved remains unknown. In this study, a systematic investigation of the effect of persistent exposure of copper in the A2O wastewater treatment system was performed. An A2O device was designed to examine the effect of copper on the removal efficiency and microbial community compositions of activated sludge that was continuously treated with 10, 20, and 40 mg L(-1) copper, respectively. Surprisingly, a decrease in chemical oxygen demand (COD) and ammonia nitrogen (NH4N) removal efficiency was observed, and the toxicity of high copper concentration was significantly greater at 7d than at 1d. Proteobacteria, Bacteroidetes, Acidobacteria, Chlorobi, and Nitrospirae were the dominant bacterial taxa in the A2O system, and significant changes in microbial community were observed during the exposure period. Most of the dominant bacterial groups were easily susceptible to copper toxicity and diversely changed at different copper concentrations. However, not all the bacterial taxa were inhibited by copper treatment. At high copper concentration, many bacterial species were stimulated and their abundance increased. Cluster analysis and principal coordinate analysis (PCoA) based on operational taxonomic units (OTUs) revealed clear differences in the bacterial communities among the samples. These findings indicated that copper severely affected the performance and key microbial populations in the A2O system as well as disturbed the stability of the bacterial communities in the system, thus decreasing the removal efficiency.
authors.affiliation: State Key Laboratory of Tropical Oceanography, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou 510301, China; Daya Bay Marine Biology Research Station, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Shenzhen 518121, China. Electronic address: flsun@scsio.ac.cn.
authors.forename: Fu-Lin
authors.initials: FL
authors.lastname: Sun
authors.affiliation: Department of Resources and Environment, Zunyi Normal College, Zunyi 563002, China.
authors.forename: Lei-Lei
authors.initials: LL
authors.lastname: Fan
authors.affiliation: Department of Environmental Engineering, Guangdong Industry Technical College, Guangzhou 510301, China.
authors.forename: Guang-Jian
authors.initials: GJ
authors.lastname: Xie
mesh_terms: D001419:Bacteria / Q000145:classification / Q000187:drug effects / Q000235:genetics*; D057919:Biological Oxygen Demand Analysis; D019149:Bioreactors / Q000382:microbiology*; D002244:Carbon / Q000737:chemistry*; D003300:Copper / Q000494:pharmacology*; D004269:DNA, Bacterial / Q000235:genetics; D059014:High-Throughput Nucleotide Sequencing / Q000379:methods*; D054892:Metagenome; D009584:Nitrogen / Q000378:metabolism*; D012722:Sewage / Q000382:microbiology*; D062065:Wastewater / Q000737:chemistry
chemical_list: D002244:Carbon; D003300:Copper; D004269:DNA, Bacterial; D009584:Nitrogen; D012722:Sewage; D062065:Wastewater
keywords: A(2)O system; Copper; Illumina MiSeq sequencing; Microbial community structure