Bioethanol Production Using Saccharomyces cerevisae Cultivated In Sugarcorn Juice

Thirumalai Nambi Thiruvengadathan, The University of Western Ontario

Abstract

For the first time, juice extracted from sugarcorn, a new Canadian energy crop, was used for bioethanol production. Physical and chemical characteristics of sugarcorn juice (SCJ) were determined. SCJ contained a maximum of 145 g/L of carbohydrates, with sucrose, glucose and fructose together contributing 80%. Effect of autoclaving and carbon filtration on juice sugars were investigated.

Shake flask fermentations using Saccharomyces cerevisiae grown in yeast extract supplemented SCJ produced a maximum of 45.6 g/L ethanol in 72 h. Bioreactor studies using un-supplemented SCJ achieved 40 g/L ethanol in 26 h, yielding a maximum of 0.46 g ethanol/g fermentable sugars, representing 90.4% of theoretical yield.

Sugarcorn’s crop features and juice characteristics were compared with those of sugarcane, sweet sorghum and energy cane. A proposed sugarcorn based bioethanol process was compared with corn and corn stover based processes. A Canadian sugarcorn (CANSUG) biorefinery was proposed for production of renewable fuels and chemicals.