Microbial fuel cell as a free-radical scavenging tool

Abstract

Microbial fuel cells (MFCs) are known for their capability to directly convert organic substrates into electricity by the biochemical activity of specific microorganisms. Availability of a proper terminal electron acceptor is crucial for this process. Free radicals, with their one or more unpaired electrons, are extremely reducible and could be considered as electron acceptors in terms of cathodic processes in MFC. During this reduction, free radicals could be transformed in the same manner as they are transformed by antioxidants. The present study investigated this opportunity by utilization of 2,2-diphenyl-1-picrylhydrazyl (150 mmol/dm 3 methanol solution) as a free-radical molecule. During the studied process, over 90% radical neutralization was observed in less than 16 hours. The results obtained demonstrate for the first time the potential of MFC type bioelectrochemical systems to serve as a free-radical scavenging tool and to provide antioxidant and anti-radical activity. In this way, this study opens a completely new field of research and application of bio-electrochemical systems.

Application of microbial fuel cell for simultaneous treatment of metallurgical and municipal wastewater - а laboratory study

“…In addition to metals, free radicals can also be used as electron acceptors in the cathodic compartment. 16 The maximum current that can be produced by an MFC depends on the actual rate of substrate biodegradation, whereas maximum theoretical cell voltage (also called electromotive force or emf ) depends on Gibbs energy change of the overall reaction and can be calculated as the difference between the standard reduction potentials of the cathodic oxidant (oxygen) and the chosen anodic substrate. 17 Power output of MFC could be enhanced by modification of electrodes and PEM using polymeric nanocomposites.…”