Simultaneous raw starch hydrolysis and ethanol fermentation by glucoamylase from Rhizoctonia solani and Saccharomyces cerevisiae

Crude glucoamylase preparation from Rhizoctonia solani was used to saccharify raw and cooked starch. Various concentrations of potato starch and wheat flour from 10-40%, w/v were used for mashing but 30% was found to be the optimal and economical. The saccharified mash yielded 5.89%, v/v ethanol in a simultaneous saccharification and fermentation process using a yeast strain Saccharomyces cerevisiae (SC-39) at 35 degrees C for 4 days. Removal of inhibitory substances from the fermenting broth through dialysis caused considerable increase in ethanol production.