Bioethanol Production from Oil Palm Trunk Fibers Using Activated Immobilized Saccharomyces cerevisiae SC90 Under Simultaneous Saccharification and Fermentation

Development in sustainable energy sources has become a concern for scientists around the globe, especially for the production of efficient biofuels. In the current study, simultaneous saccharification and fermentation (SSF) process with activated immobilized Saccharomyces cerevisiae SC90 was used to reduce the production cost of ethanol from alkaline-pretreated oil palm trunk (OPT) fibers owing to the reusable property of immobilized Saccharomyces cerevisiae SC90 cells. The highest ethanol concentration of 104.52 g/L using glucose as substrate was observed with immobilized Saccharomyces cerevisiae SC90 cells in first 48 h of fermentation. In contrast, at similar stage, the free cells managed to produce ethanol concentration of 85.87 g/L. The SSF process was carried out with 10% (w/v) and 20% (w/v) OPT fibers as carbon source to produce ethanol without adding extra nutrients in batch and fed-batch SSF process with activated immobilized cells of Saccharomyces cerevisiae SC90. The maximum ethanol concentration and ethanol yield using batch SSF were 29.68 g/L and 0.32 g/g, respectively. However, in fed-batch SSF, the maximum ethanol concentration and yield were 51.68 g/L and 0.28 g/g, respectively. The results depicted that activated immobilized cells of Saccharomyces cerevisiae SC90 can produce ethanol without nitrogen source which is an encouraging approach to attain cost-effective 2G ethanol production from pretreated oil palm trunk (OPT) fibers.