Responses of electroactive biofilms to chronic chlorine exposure: Insights from the composition and spatial structure of extracellular polymeric substances

Yue Dong; Mingrui Sui; Xin Wang; Peng Zhang; Yiying Jiang; Jianyu Wu

doi:10.1016/j.bioelechem.2021.107894

Responses of electroactive biofilms to chronic chlorine exposure: Insights from the composition and spatial structure of extracellular polymeric substances

Bioelectrochemistry. 2021 Dec:142:107894. doi: 10.1016/j.bioelechem.2021.107894. Epub 2021 Jul 27.

Authors

Yue Dong¹, Mingrui Sui², Xin Wang³, Peng Zhang⁴, Yiying Jiang¹, Jianyu Wu¹

Affiliations

¹ Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes of Ministry of Education, College of Environment, Hohai University, Nanjing 210098, China.
² College of Water Conservancy and Hydropower Engineering, Hohai University, Nanjing 210098, China. Electronic address: suimingruihit@163.com.
³ MOE Key Laboratory of Pollution Processes and Environmental Criteria and Tianjin Key Laboratory of Environmental Remediation and Pollution Control, College of Environmental Science and Engineering, Nankai University, Tianjin 300350, China.
⁴ Faculty of Environmental Science and Engineering, Kunming University of Science and Technology, Kunming 650500, China.

Abstract

Extensive amounts of chlorine disinfectants have been applied to wastewater system since the outbreak of coronavirus disease 2019 (COVID-19), which inevitably affects the pollutant degradation via interfering with electron transfer mediated by electroactive bacteria. Herein, the response of electroactive biofilm (EAB) to chronic chlorine exposure was investigated. Results showed the EAB formed without exposure (EAB-0) exhibited a 53% and 123% higher current output than that formed with 0.1 mg L^-1 (EAB-0.1) and 0.5 mg L^-1 (EAB-0.5) chlorine, respectively. The chronic chlorine exposure of EAB boosted the contents of extracellular polymeric substances (EPS) in EAB-0.1 and EAB-0.5 by over secretion of extracellular polysaccharides. The EAB-0.1 and EAB-0.5 also presented lower electron exchange capacities (EECs) of EPS, coincided with reduced relative abundance of Geobacter from 61% in EAB-0 to 52% in EAB-0.5. This study provided new insights into the application of engineered EAB for wastewater treatment in a disinfection environment.

Keywords: Chronic chlorine exposure; Electroactive biofilms (EABs); Electron exchange capacities; Extracellular polymeric substances (EPS); Pollutant degradation.

Publication types

Comparative Study

MeSH terms

Biofilms / drug effects*
Chlorine / pharmacology*
Disinfectants / pharmacology*
Extracellular Polymeric Substance Matrix / metabolism*
Time Factors

Substances

Disinfectants
Chlorine