Simultaneous Saccharification and Fermentation of Sorghum Bicolour Grains by Ethanol and Sugar Tolerated Saccharomyces cerevisiae

Abstract

Saccharomyces cerevisiae was used to evaluate sugar tolerance and efficient production of ethanol from Sorghum bicolour grains. The results revealed that the strain tolerates ethanol up to 11 % (v/v) and glucose level up to 25 % (w/v). Simultaneous saccharification and fermentation was used to produce ethanol from grain starch of different Sorghum bicolour varieties by utilizing and yeast strain S. cerevisiae. The samples (20 %, w/v) were liquefied at different temperatures (85-100 ºC) for complete conversion of starch into oligosaccharide and saccharification. Separate hydrolysis and fermentation results showed that 70.84 to 82.12 gL^-1 ethanol was produced with the highest 95 % fermentation efficiency at 60 ºC. Simultaneous saccharification and fermentation resulted in a slightly higher concentration of ethanol. It was observed that sugar produced from starch was promptly used up for fermentation in both separate hydrolysis and fermentation and simultaneous saccharification and fermentation.