Protection of electroactive biofilms against hypersaline shock by quorum sensing

Shaofeng Zhou; Wenwen An; Kexin Zhao; Lizhou Lin; Shan Yang; Yifeng Zhang; Meiying Xu

doi:10.1016/j.watres.2023.119823

Protection of electroactive biofilms against hypersaline shock by quorum sensing

Water Res. 2023 Apr 15:233:119823. doi: 10.1016/j.watres.2023.119823. Epub 2023 Mar 1.

Authors

Shaofeng Zhou¹, Wenwen An², Kexin Zhao³, Lizhou Lin², Shan Yang², Yifeng Zhang⁴, Meiying Xu⁵

Affiliations

¹ Guangdong Provincial Key Laboratory of Microbial Culture Collection and Application, State Key Laboratory of Applied Microbiology Southern China, Institute of Microbiology, Guangdong Academy of Sciences, Guangzhou 510070, China; Guangdong Key Laboratory of Environmental Catalysis and Health Risk Control, School of Environmental Science and Engineering, Institute of Environmental Health and Pollution Control, Guangdong University of Technology, Guangzhou 510006, China.
² Guangdong Provincial Key Laboratory of Microbial Culture Collection and Application, State Key Laboratory of Applied Microbiology Southern China, Institute of Microbiology, Guangdong Academy of Sciences, Guangzhou 510070, China.
³ Institute of Eco-environmental and Soil Sciences, Guangdong Academy of Sciences, Guangzhou 510650, China.
⁴ Department of Environmental and Resource Engineering, Technical University of Denmark, Lyngby DK-2800, Denmark.
⁵ Guangdong Provincial Key Laboratory of Microbial Culture Collection and Application, State Key Laboratory of Applied Microbiology Southern China, Institute of Microbiology, Guangdong Academy of Sciences, Guangzhou 510070, China. Electronic address: xumy@gdim.cn.

PMID: 36871386
DOI: 10.1016/j.watres.2023.119823

Abstract

Quorum sensing (QS) is an ideal strategy for boosting the operating performance of electroactive biofilms (EABs), but its potential effects on the protection of electroactive biofilms against environmental shocks (e.g., hypersaline shock) have been rarely revealed. In this study, a QS signaling molecule, the N-(3-oxo-dodecanoyl)-L-homoserine lactone, was employed to promote the anti-shock property of the EABs against extreme saline shock. The maximum current density of the QS-regulated biofilm recovered to 0.17 mA/cm² after 10% salinity exposure, which was much higher than those of its counterparts. The laser scanning confocal microscope confirmed a thicker and more compact biofilm with the presence of the QS signaling molecule. The extracellular polymeric substances (EPS) might play a crucial role in the anti-shocking behaviors, as the polysaccharides in EPS of QS-biofilm had doubled compared to the groups with acylase (the QS quencher). The microbial community analysis indicated that the QS molecule enriched the relative abundance of key species including Pseudomonas sp. and Geobacter sp., which were both beneficial to the stability and electroactivity of the biofilms. The functional genes related to the bacterial community were also up-regulated with the presence of the QS molecule. These results highlight the importance of QS effects in protecting electroactive biofilm under extreme environmental shock, which provides effective and feasible strategies for the future development of microbial electrochemical technologies.

Keywords: Electroactive biofilms; Extracellular polymeric substances; Hypersaline shock; Protective strategy; Quorum sensing.

MeSH terms

Bacteria
Biofilms*
Lactones
Pseudomonas
Quorum Sensing*

Substances

Lactones