Bioethanol Production from Red Banana Waste via Saccharomyces cerevisiae under Optimized Conditions

Abstract

Red banana waste (Musa acuminata) residue (leaves, pseudostems, banana peels, banana stalks, and flowers) was used to produce bioethanol via Saccharomyces cerevisiae. The banana waste was dried and pretreated individually with sodium hydroxide and sulfuric acid. Alkaline treatment increased the reducing sugar content more than acid hydrolysis. Bioethanol production from banana residue via enzyme saccharification and fermentation was performed via the filter paperase enzyme and fermentation via S. cerevisiae. The bioethanol production was temperature dependent. Maximum production was achieved at 36 °C (27.3 ± 0.3 g/L), after 96 h (30.4 ± 1.1 g/L), at a 7.5% substrate concentration (33.5 ± 0.91 g/L) and at pH 5.0 (36.2 ± 0.48 g/L). The maximum bioethanol production was achieved by the immobilized S. cerevisiae cells after 96 h of fermentation (39.8 ± 0.55 g/L). Moreover, at this stage, bioethanol production was 35.9 ± 0.51 g/L in S. cerevisiae-free fermentation. The bioethanol yield was 11% greater in the immobilized culture than in the free-cell fermentation after four days. Beyond its renewable energy role, bioethanol reduces fossil fuel emissions associated with neurological and developmental disabilities, a connection that will be evaluated in forthcoming research.