Enzyme Fuel Cell for Cellulolytic Sugar Conversion Employing FAD Glucose Dehydrogenase and Carbon Cloth Electrode Based on Direct Electron Transfer Principle

An enzyme fuel cell employing a carbon cloth electrode and bacterial FAD dependent glucose dehydrogenase (FADGDH) based on the direct electron transfer principle was constructed, and its scalability and cellulolytic sugar conversion were investigated. FADGDH was immobilized on the carbon cloth electrode together with carbon paste to form a multi-module type enzyme fuel cell by combining platinum-supported carbon immobilized carbon cloth as the cathode. The enzyme fuel cell was stable for more than 7 days of continuous operation. The 3 3 module (18 cm 2 ) enzyme fuel cell generated 68 μW (3.8 μW/cm 2 ) using glucose as the substrate, which was almost 9 times that of a single-module enzyme fuel cell. Thanks to the substrate specificity of bacterial FADGDH, cellulolytic sugars were revealed to be a good substrate for the enzyme fuel cell with cellobiose (9.3 μW/cm 2 ), cellotriose (9.2 μW/cm 2 ), or cellotetraose (6.3 μW/cm 2 ). These results demonstrated that together with the feasibility of using carbon cloth as the electrode material, FADGDH as the anode catalyst will become the norm in electrochemical biomass applications in the future.