(561e) The Effect of Electron Donor On Microbial Fuel Cell Performance

Microbial fuel cells (MFCs) are a fuel cell technology that utilizes microorganisms as catalysts in the conversion of electron donors into electrical power. Similar to traditional fuel cells, MFCs can be set up in two-chamber systems separating the anode and cathode chambers by a proton exchange membrane (PEM). Unlike traditional hydrogen or methanol fuel cells which efficiently utilize a single energy source, MFCs are capable of utilizing a variety of electron donors. The spectrum of electron donors is dependent upon the metabolic capabilities of the microorganism that is selected as the biocatalyst for the process. The ability of MFCs to utilize the wide variety of electron donors, brings up the question what the power production is under these different substrates, which will be important for applications using a variety of energy sources.

In these studies, the γ-proteobacterium Pseudomonas aeruginosa (PAO1) was utilized as the anode biocatalyst to process a variety of electron donors. An H-style MFC utilizing 1 mil Nafion^® PEM with 175 mL anode and cathode chambers was utilized to assess the electrical production performance of a variety of electron donors (glucose, formate, succinate, acetate, and cellobiose). The anode was carbon cloth and the cathode was platinum foil. Mineral salt medium supplemented with 5 g/L of each individual substrate was as the anolyte. Succinate and glucose were the most effective catalysts in terms of power production at 46 and 41 mW/m². No observable power was produced from formate, acetate, or cellobiose. This electricity production by P. aeruginosa from glucose and succinate, but not formate, acetate, or cellobiose indicates that the composition of the electron donor feed sources needs to be considered when implementing microbial fuel cells utilizing complex feed sources.