BIOCONVERSION OF CASSAVA ROOT TO ETHANOL BY CO-CULTIVATION OF AMYLOLYTIC ENZYME PRODUCTION MOULD AND SACCHAROMYCES CEREVISIAE

บทคัดย่อ

This work was to study the bioethanol production from cassava root using co-fermentation with fungi (Aspergillus niger, Rhizopus oligosporus and Trichoderma reesei) and Saccharomyces cerevisiae. The ethanol fermentation from cassava root, one important step in pretreatment is Liquefaction. In this step, the α-amylase enzyme is used to hydrolyze starch in cassava root to get smaller molecules and lower viscosity. For cassava powder (5% w/v) hydrolysis, co-culture of A. niger with R. oligosporus gave highest reducing sugar of 25.1 g/l at 5th day of cultivation. The highest ethanol of 12.9 g/l was achieved by using R.oligosporus, A. niger and T. reesei for 5 days-fungi fermentation and subsequent ethanol fermentation by co-cultivation with S. cerevisiae for 18 hours. Using alpha-amylase liquefaction, R. oligosporus fermentation, centrifugation and then S. cerevisiae fermentation, ethanol concentration of 45 g/l was found in 24 hours.