(193c) Improving Electrode Performance By Engineering Shewanella Oneidensis MR1

Microbial fuel cell (MFC) is a device that can treat wastewater and generate electricity simultaneously, which has attracted much attention in recent years. However, several disadvantages, such as the cost of electrode materials, the low buffering capacity of domestic wastewater, and low electron transfer efficiency or low energy production, limit the MFC full-scale application in the industry. One of the main reasons behind the low power density produced by MFC is the slow transfer of electrons from the microorganism to the anode surface. The formation and characteristics of biofilms on the anode of MFC determine the performance of the system. The biofilm that grows on the electrode of the MFC is called electrochemically active, which is the hallmark of the electronic transfer ability with the electrodes. Extracellular electron transfer (EET) is a crucial process by which electricity-producing bacteria transfer biologically generated electrons to extracellular electrodes. Shewanella oneidensis has been studied and applied in the biodegradation process of wastewater treatment because of its excellent EET properties. We improved the biofilm formation of S. oneidensis by enhancing curli biogenesis and c-di-GMP production. Current density and cyclic voltammetry are measured through a single chamber cell by developing biofilms of our engineered S. oneidensis on the commercial glassy carbon electrode. We test efficiency of the bisphenol A degradation and electricity generation with improved biofilm formation of S. oneidensis in a single chamber cell. This study will reveal the relation between biofilm-electrode performance and enhanced electron transfer, promoting the application of MFC.