Complexing agents-free bioelectrochemical trickling systems for highly-efficient mesothermal NO removal: The role of extracellular polymer substances

Xingzhu Huang; Shaofeng Zhou; Jianjun Li; Xiaojun Wang; Shaobin Huang; Guoping Sun; Shan Yang; Jia Xing; Meiying Xu

doi:10.1016/j.biortech.2022.128286

Complexing agents-free bioelectrochemical trickling systems for highly-efficient mesothermal NO removal: The role of extracellular polymer substances

Bioresour Technol. 2023 Jan:368:128286. doi: 10.1016/j.biortech.2022.128286. Epub 2022 Nov 9.

Authors

Xingzhu Huang¹, Shaofeng Zhou¹, Jianjun Li², Xiaojun Wang³, Shaobin Huang³, Guoping Sun⁴, Shan Yang⁴, Jia Xing⁴, Meiying Xu⁵

Affiliations

¹ School of Environment and Energy, South China University of Technology, Higher Education Mega Center, Guangzhou 510006, China; Guangdong Provincial Key Laboratory of Microbial Culture Collection and Application, State Key Laboratory of Applied Microbiology Southern China, Guangdong Institute of Microbiology, Guangdong Academy of Sciences, Guangzhou 510070, China.
² School of Life Sciences and Engineering, Foshan University, Foshan, Guangdong Province, China.
³ School of Environment and Energy, South China University of Technology, Higher Education Mega Center, Guangzhou 510006, China.
⁴ Guangdong Provincial Key Laboratory of Microbial Culture Collection and Application, State Key Laboratory of Applied Microbiology Southern China, Guangdong Institute of Microbiology, Guangdong Academy of Sciences, Guangzhou 510070, China.
⁵ Guangdong Provincial Key Laboratory of Microbial Culture Collection and Application, State Key Laboratory of Applied Microbiology Southern China, Guangdong Institute of Microbiology, Guangdong Academy of Sciences, Guangzhou 510070, China. Electronic address: xumy@gdim.com.

PMID: 36368487
DOI: 10.1016/j.biortech.2022.128286

Abstract

The biological treatments are promising for nitric oxide (NO) reduction, however, the biotechnology has long suffered from high demands of NO-complexing agents (i.e., Fe(II)EDTA), leading to extra operation costs. In this study, novel complexing agents-free bioelectrochemical systems have been developed for direct NO reduction. The electricity-driven bioelectrochemical trickling system (ED-BTS, a denitrifying biocathode driven by the external electricity and an acetate-consuming bioanode) achieved approximately 68% NO removal without any NO-complexing agents, superior to the bioanode-driven BTS and open-circuit BTS. The extracellular polymeric substances from the biofilms of ED-BTS contained more polysaccharides, humic substrates, and hydrophobic tryptophan that were beneficial for NO reduction. Additionally, the external electricity altered the microbial community toward more denitrifying bacteria and a higher abundance of NO reduction genes (nosZ and cnorB). This study provides a comprehensive understanding of microbial behaviors on the adsorption and reduction of NO and proposes a promising strategy for mesothermal NO biotreatment.

Keywords: Bioelectrochemical trickling systems; Denitrifying genes; Electrochemical biofilm; Extracellular polymeric substances; Nitric oxide.

MeSH terms

Biofilms
Electricity
Electrodes
Extracellular Polymeric Substance Matrix*
Nitric Oxide*
Polymers

Substances

Nitric Oxide
Polymers