Simultaneous co-Saccharification and Fermentation of Sago Hampas for Bioethanol Production
Keywords:Bioethanol, sago hampas, Simultaneous co-Saccharification and Fermentation (Sc-SF), amylase, cellulase, Saccharomyces cerevisiae, HPLC.
Abundance of lignocellulosic biomass provides a good solution to the demands of energy crops in producing biofuel like biodiesel and bioethanol. In this study, bioethanol was produced from sago hampas via the Simultaneous co-Saccharification and Fermentation (Sc-SF) process, at 2.5% and 5.0% (w/v) solid loadings. The processing step in Sc-SF is virtually similar to that of Simultaneous Saccharification and Fermentation (SSF). However, during Sc-SF, two enzymes, amylase and cellulase, were added for the co-saccharification of sago starch and fiber. In addition, Saccharomyces cerevisiae was used to ferment the sugars in the hydrolysates. The Sc-SF samples were analyzed for carbohydrate residues, ethanol and acetic acid using the dinitrosalicylic (DNS) acid assay and High Performance Liquid Chromatography (HPLC). Results showed that the Sc-SF of the sago hampas showed high efficiencies of hydrolysis and ethanol production within the first 6 hours of fermentation. Highest glucose production was at 37.86 g/l for the 5.0% sago hampas load and 17.47 g/l for 2.5% sago hampas load. The highest ethanol production was observed in the broth with 5.0% sago hampas, with the theoretical yield of 80.50%. Meanwhile, the highest bioethanol yield in the sample with 2.5% sago hampas was 73.19%. This study indicated that there is feasibility of bioethanol production via Sc-SF from starch rich agricultural residues such as sago hampas.