SACCHARIFICATION AND ALCOHOL FERMENTATION IN STARCH SOLUTION OF STEAM-EXPLODED POTATO

Steam explosion pretreatment of potato for the efficient production of alcohol was experimentally studied. The amount of water-soluble starc h increased with the increase of steam pressure, but the amounts of me thanol-soluble material and Klason lignin remained insignificant, rega rdless of steam pressure. The potatoes exploded at high pressure were hydrolyzed into a low molecular liquid starch, and then easily convert ed into ethanol by simultaneous saccharification and fermentation usin g mixed microorganisms: an amylolytic microorganism, Aspergillus awamo ri, and a fermentation microorganism, Saccharomyces cerevisiae. The ma ximal ethanol concentration was 4.2 g/L in a batch culture at 15 g/L s tarch concentration, and 3.6 g/L in a continuous culture fed the same starch concentration. In the fed-batch culture, the maximal ethanol co ncentration increased more than twofold, compared to the batch culture .