Enhanced Bioelectrocatalysis of Shewanella oneidensis MR-1 by a Naphthoquinone Redox Polymer

Shewanella oneidensis MR-1 is the model organism used in microbial fuel cells (MFCs). A great deal of research has focused on this bacterium to improve extracellular electron transfer (EET) and subsequently the power output in MFCs. Here, we report on the enhanced bioelectrocatalysis of S. oneidensis MR-1 by using a naphthoquinone redox polymer (NQ-LPEI) on a modified carbon felt electrode. A maximum anodic current of 3.70 ± 0.40 Am-2 is obtained in a three-electrode setup, a value 15 times higher than that obtained for an anode that did not contain the NQ-LPEI redox polymer (0.24 ± 0.05 Am-2). Additionally, a maximum power output of 0.53 ± 0.02 Wm-2 was obtained in single-chamber MFCs where the NQ-LPEI modified anode was utilized. The power output was significantly higher than that obtained for MFCs with unmodified anodes (0.19 ± 0.05 Wm-2). These findings suggest that NQ-LPEI could be used with known electrogenic microorganisms to further improve the performances of MFCs.