Electron shuttle-dependent biofilm formation and biocurrent generation: Concentration effects and mechanistic insights

Frontiers in Microbiology

Microbiology

Wei Liu¹  Xiao Zhu²  Fangbai Li³  Yundang Wu³  Fei Dou³  Tongxu Liu³  Xinxin Wang⁴  Mingliang Long⁴ 

[1] College of Materials and Energy, South China Agricultural University, Guangzhou, China;Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou, China;National-Regional Joint Engineering Research Center for Soil Pollution Control and Remediation in South China, Guangzhou, China;Guangdong Key Laboratory of Integrated Agro-environmental Pollution Control and Management, Institute of Eco-environmental and Soil Sciences, Guangdong Academy of Sciences, Guangzhou, China;University of Chinese Academy of Sciences, Beijing, China;National-Regional Joint Engineering Research Center for Soil Pollution Control and Remediation in South China, Guangzhou, China;Guangdong Key Laboratory of Integrated Agro-environmental Pollution Control and Management, Institute of Eco-environmental and Soil Sciences, Guangdong Academy of Sciences, Guangzhou, China;National-Regional Joint Engineering Research Center for Soil Pollution Control and Remediation in South China, Guangzhou, China;Guangdong Key Laboratory of Integrated Agro-environmental Pollution Control and Management, Institute of Eco-environmental and Soil Sciences, Guangdong Academy of Sciences, Guangzhou, China;College of Materials and Energy, South China Agricultural University, Guangzhou, China;

关键词: electron shuttle;    extracellular electron transfer (EET);    biofilm;    Shewanella oneidensis;    electroactive bacteria (EAB);   

DOI  :  10.3389/fmicb.2023.1070800

 received in 2022-10-15, accepted in 2023-01-31,  发布年份 2023

来源: Frontiers

【 摘 要 】

IntroductionElectron shuttles (ESs) play a key role in extracellular electron transfer (EET) in Shewanella oneidensis MR-1. However, the quantification relationship between ES concentration, biofilm formation, and biocurrent generation has not been clarified.MethodsIn this study, 9,10-anthraquinone-2-sulfonic acid (AQS)-mediated EET and biofilm formation were evaluated at different AQS concentrations in bioelectrochemical systems (BESs) with S. oneidensis MR-1.Results and discussionBoth the biofilm biomass (9- to 17-fold) and biocurrent (21- to 80-fold) were substantially enhanced by exogenous AQS, suggesting the dual ability of AQS to promote both biofilm formation and electron shuttling. Nevertheless, biofilms barely grew without the addition of exogenous AQS, revealing that biofilm formation by S. oneidensis MR-1 is highly dependent on electron shuttling. The biofilm growth was delayed in a BES of 2,000 μM AQS, which is probably because the redundant AQS in the bulk solution acted as a soluble electron acceptor and delayed biofilm formation. In addition, the maximum biocurrent density in BESs with different concentrations of AQS was fitted to the Michaelis–Menten equation (R2 = 0.97), demonstrating that microbial-catalyzed ES bio-reduction is the key limiting factor of the maximum biocurrent density in BESs. This study provided a fundamental understanding of ES-mediated EET, which could be beneficial for the enrichment of electroactive biofilms, the rapid start-up of microbial fuel cells (MFCs), and the design of BESs for wastewater treatment.

【 授权许可】

Unknown   
Copyright © 2023 Zhu, Dou, Long, Wang, Liu, Li, Liu and Wu.