Integrated process development for the efficient and industrial production of 2,3-butanediol and bioethanol using dried cassava chips as commercial biomass

BACKGROUND: For the efficient use of cassava as industrial material in the fermentation business, an integrated process was developed to produce 2,3-butanediol (2,3-BDO) and bioethanol (BE) by a highly efficient and economical method. After separating the liquefied cassava into a solid and a liquid part, the liquid part was used to produce 2,3-BDO, and the solid part was then used to produce BE. RESULTS: The integrated process efficiently fermented 1000 g of dried cassava to 288 g of 2,3-BDO (120.1 g L⁻¹ titer and 2.39 L fermented broth) and 57 g of BE (38.4 g L⁻¹ titer and 1.49 L fermented broth). Also, fermentable sugar of cassava was 100% available for this process, and the byproduct of BE production, condensed distillers solubles (CDS), was used as a potential nutrient source for the economical production of 2,3-BDO. CONCLUSION: An integrated process with simultaneous saccharification and fermentation (SSF), pH shift, and rpm shift was developed to enhance 2,3-BDO production and to reduce the production cost of 2,3-BDO and BE. The strategy of employing cassava as a starchy biomass-based biorefinery resource for 2,3-BDO and BE production was successfully performed.