Microbial Biofilm Development and Electron Transfer in Electrochemical Systems
Energy harvesting from microorganisms has created vibrant research efforts for the past 20 years that has lead to the development of emerging topics such as microbial electrochemistry, biofilm formation in electrochemical systems and alternative energy technologies applied in environmental processes. In this study we present procedures that aim for further understanding of bacterial physiological conditions in electrochemical systems and interactions between biofilms and solid surfaces, particularly, for the facultative anaerobe Shewanella oneidensis MR-1. These systems consist of microbial fuel cells (MFCs) whose anode component will be evaluated with regards to performance, electrical current generation, and microbial coverage and biofilm development. A better understanding of how anode surface properties affect growth, development, and activity of electrogenic biofilms has great potential to improve the performance of bioelectrochemical systems such as MFCs. A combination of spectroscopic, microscopic, and electrochemical techniques was used to evaluate how electrode surface chemistry influences morphological, chemical, and functional properties of wild type S. oneidensis and motility-impaired mutant strains, as well as mixed cultures found in wastewater treatment plants. This was done with an effort to develop improved electrode materials by studying structure-to-property relationships. 3D morphological features of biofilms that were directly linked to functional properties of the biofilm during growth during polarization were directly connected to the efficiency of electron transfer from the bacteria to the anode.
Micorbial fuel cells, Shewanella, Bioelectrochemistry, Anodic current, Biofilm formation, Chemical Engineering
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