The use of commercial wine yeast Saccharomyces cerevisiae EC1118 for cassava ethanol production at high solids loading

Abstract

Cassava is one of the most commonly imported raw materials for ethanol fermentation for the manufacture of food-grade distilled spirits in Korea. In cassava-producing countries, such as the Lao PDR, cassava can be considered low-price biomass for the production of bioethanol. In this study, the commercial wine yeast Saccharomyces cerevisiae EC1118 was tested for ethanol fermentation using cassava powder at a high solids loading (30%, w/v). α-Amylase and glucoamylase were used for the hydrolysis of cassava starch into glucose. To identify a suitable fermentation process for cassava, separate hydrolysis and fermentation (SHF) and simultaneous saccharification and fermentation (SSF) were compared. From the complete enzyme hydrolysis of cassava, 254.1 g/L of glucose was obtained. SSF showed higher ethanol titer during the first 12 h of fermentation, but SHF showed a higher ethanol titer after 24 h of fermentation. Finally, there was no significant difference between SHF and SSF in the final ethanol titer after 48 h fermentation (133.6 and 130.6 g/L, respectively). In summary, both SHF and SSF are applicable for ethanol production with high solid cassava using wine yeast EC1118 under the test conditions.