MICROBIAL FUEL-CELLS - ELECTRICITY PRODUCTION FROM CARBOHYDRATES

Microbial fuel cells containing Proteus vulgaris and oxidation-reducti on (''redox'') mediators were investigated. The bacteria were chemical ly immobilized onto the surface of graphite felt electrodes, which sup ported production of continuous electric current and could be reused a fter storage. A computer-controlled carbohydrate feed system enabled t he cell to generate a constant output with improved efficiency compare d to the performance obtained with single large additions of fuel. The response to additions of substrate when immobilized bacteria were use d was faster than that achieved with freely suspended organisms. This is attributed to the advantageous mass-transfer kinetics resulting fro m the proximity of the immobilized bacteria and the electrode surface.