Abstract
Hydrolysis with cellulase (saccharification) and bioethanol production (fermentation) by Saccharomyces cerevisiae IR-2 strain was investigated in an onion. In saccharification, glucose and fructose increased with time and became a maximum at 20 hours, although sucrose decreased with time. In fermentation, the content of ethanol converted by S. cerevisiae IR-2 strain increased rapidly with time and became a maximum within 32 hours in solution with 14.8mg·mL−1. The temperature of fermentation was optimal in the range of 30°C to 35°C. Findings show that the free cells of S. cerevisiae IR-2 strain do not recognize ethanol production in simultaneous saccharification and fermentation. On the other hand, the immobilized cells of S. cerevisiae IR-2 strain note ethanol production in simultaneous saccharification and fermentation. These results suggest that simultaneous saccharification and fermentation by immobilized cells was useful for ethanol production in an onion.
