Effect of Temperature and Inoculum Concentration on Cassava Peel-Based Bioethanol Fermentation Using Kluyveromyces marxianus UB5 Suprayogi*, Trining Rahayu, Sri Suhartini, Nimas Mayang Sabrina
Department of Agroindustrial Technology,
Faculty of Agricultural Technology, Universitas Brawijaya
email: suprayogi99[at]ub.ac.id
Abstract
Indonesia growing population has led to an increase in transportation energy needs, but dependence on fossil fuels is no longer sustainable. Bioethanol can be an alternative renewable fuel through fermentation. One waste product that can be converted into bioethanol is cassava peel, which contains lignocellulose (second generation) through separated hydrolysis and fermentation (SSF). One food industry that produces significant cassava peel waste is the tapioca flour industry. Furthermore, the high cellulose content of cassava peel, at 43.626%, makes it a potential raw material for bioethanol. Therefore, the purpose of this study was to analyze and evaluate the effect and determine the best combination of temperature and inoculum concentration on bioethanol production from cassava peel using the yeast Kluyveromyces marxianus UB5. This research method used a factorial Randomized Block Design (RBD) with two factors fermentation temperature (37C, 40C, and 43C) and inoculum concentration (10% (v/v), 12.5% (v/v), and 15% (v/v). The fermentation results showed the best treatment combination was the temperature treatment of 37C and an inoculum concentration of 15% (T1C3). At the end of fermentation or the 48th hour, the T1C3 treatment produced bioethanol with an average pH value of 4.54, total sugars 0.775%, total reducing sugars 0.978%, and an increase in OD of 0.40. The ethanol content produced in the T1C3 treatment was 0.662%, with an ethanol yield of 12.820% and a fermentation efficiency of 25.087%. Based on the very low ethanol content, further research is needed to determine factors that can maximize bioethanol production.
Keywords: K. marxianus UB5- Inoculum Concentration- Cassava Peel- Temperature
