Ethanol Conversion of Spent Mushroom Culture Medium by the Ball-Vibration Simultaneous Saccharification and Fermentation System

The "Ball-Vibration Simultaneous Saccharification and Fermentation system" was tested for more effective conversion of the spent Maitake (Grifola frondosa) culture medium to ethanol. This system converts biomass to ethanol in one vessel containing cellulase, yeast and small balls with vibration. In this system, high ethanol yield was obtained, but ethanol fermentation was inhibited during continuous vibration. This inhibition was relieved by using intermittent ball vibration which alternates stationary culture and vibrating culture, and consequently ethanol fermentation time was significantly decreased and ethanol yield was 1.3 times higher than for vibration without balls. Therefore, the Ball-Vibration SSF system was effective for increased ethanol conversion rate of the spent Maitake culture medium. It is likely that this system would also be effective for ethanol conversion of various types of biomass.