ELECTROCHEMICAL CHARACTERISTICS OF SHEWANELLA LOIHICA PV-4 ON RETICULATED VITREOUS CARBON (RVC) WITH DIFFERENT POTENTIALS APPLIED
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Date
2022
Authors
Wang, Shixin
Zhang, Xiaoming
Marsili, Enrico
Journal Title
Journal ISSN
Volume Title
Publisher
Molecules
Abstract
The current output of an anodic bioelectrochemical system (BES) depends upon the
extracellular electron transfer (EET) rate from electricigens to the electrodes. Thus, investigation of
EET mechanisms between electricigens and solid electrodes is essential. Here, reticulated vitreous
carbon (RVC) electrodes are used to increase the surface available for biofilm formation of the known
electricigen Shewanella loihica PV-4, which is limited in conventional flat electrodes. S. loihica PV-
4 utilizes flavin-mediated EET at potential lower than the outer membrane cytochromes (OMC),
while at higher potential, both direct electron transfer (DET) and mediated electron transfer (MET)
contribute to the current output. Results show that high electrode potential favors cell attachment on
RVC, which enhances the current output. DET is the prevailing mechanism in early biofilm, while
the contribution of MET to current output increased as the biofilm matured. Electrochemical analysis
under starvation shows that the mediators could be confined in the biofilm. The morphology of
biofilm shows bacteria distributed on the top layer of honeycomb structures, preferentially on the
flat areas. This study provides insights into the EET pathways of S. loihica PV-4 on porous RVC
electrodes at different biofilm ages and different set potential, which is important for the design of
real-world BES.
Description
Keywords
Type of access: Open Access, reticulated vitreous carbon (RVC), Shewanella loihica PV-4, biofilm formation, direct electron transfer (DET), mediated electron transfer (MET), bioelectrochemical systems (BES)
Citation
Wang, S., Zhang, X., & Marsili, E. (2022). Electrochemical Characteristics of Shewanella loihica PV-4 on Reticulated Vitreous Carbon (RVC) with Different Potentials Applied. Molecules, 27(16), 5330. https://doi.org/10.3390/molecules27165330