Responses of nitrification performance,triclosan resistome and diversity of microbes to continuous triclosan stress in activated sludge system  

作　　者：Da Zhang Jingfeng Gao Lifang Zhang Wenzhi Zhang Jingxin Jia Huihui Dai Zhiqi Wang 

机构地区：[1]National Engineering Laboratory for Aduanced Municipal Wastewater Treatment and Reuse Technology,College of Environmental and Energy Engineering,Beijing University of Technology,Beijing 100124,China

出　　处：《Journal of Environmental Sciences》2020年第6期211-223,共13页环境科学学报（英文版）

基　　金：supported by the National Natural Science Foundation of China(No.51578015);the Beijing Natural Science Foundation(No.8202006);the National Science and Technology Major Project(No.2017ZX07103-003);the Beijing Municipal Science and Technology Project(No.Z181100005518002)。

摘　　要：Triclosan(TCS)is commonly found in wastewater treatment plants,which often affects biological treatment processes.The responses of nitrification,antibiotic resistome and microbial community under different TCS concentrations in activated sludge system were evaluated in this study.The experiment was conducted in a sequencing batch reactor(SBR)for 240 days.Quantitative PCR results demonstrated that the abundance of ammonium oxidizing bacteria could be temporarily inhibited by 1 mg/L TCS and then gradually recovered.And the abundances of nitrite oxidizing bacteria(NOB)under 2.5 and 4 mg/L TCS were three orders of magnitude lower than that of seed sludge,which accounted for partial nitrification.When the addition of TCS was stopped,the abundance of NOB increased.The mass balance experiments of TCS demonstrated that the primary removal pathway of TCS changed from adsorption to biodegradation as TCS was continuously added into the SBR system.Moreover,TCS increased the abundance of mexB,indicating the efflux pump might be the main TCS-resistance mechanism.As a response to TCS,bacteria could secrete more protein(PN)than polysaccharide.Three-dimensional excitation-emission matrix revealed that tryptophan PN-like substances might be the main component in PN to resist TCS.High-throughput sequencing found that the relative abundances of Paracoccus,Pseudoxanthomonas and Thauera increased,which could secrete extracellular polymeric substances(EPS).And Sphingopyxis might be the main TCS-degrading bacteria.Overall,TCS could cause partial nitrification and increase the relative abundances of EPS-secreting bacteria and TCS-degrading bacteria.

关 键 词：TRICLOSAN Partial nitrification Nitrite oxidizing bacteria Triclosan resistome Microbial community 

分 类 号：X703[环境科学与工程—环境工程]