Abstract

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This study investigated the production of bioethanol from sugarcane bagasse in an optimized condition. Optimization of production medium helps to maximise metabolite yield. The capacity of Saccharomyces cerevisiae to ferment wort derived from sugarcane bagasse, an agricultural waste, in optimized conditions to produce bioethanol, was studied. A box-behnken design of five factors (substrate weight, temperature, inoculum size, pH, incubation time) and three levels was adopted to improve production efficiency. The substrate was subjected to physical and biological pretreatments to obtain simple sugars. Cellulase enzyme was used to breakdown the substrate to simpler sugars. Alcoholic fermentation was done using S. cerevisiae for six days. Brix content was measured before and during the fermentation process, as well as alcohol content after fermentation. Response surface plots of the factors were plotted. The results showed that brix value ranged from 2.3 oBx to 3.9 oBx while bioethanol production ranged from 1.38g/l to 2.35g/l. At optimal conditions of pH 6, temperature of 40oC, inoculum size of 4, substrate weight of 10g and fermentation time of 72h, predicted ethanol yield will be 4.23g/l. Sugarcane bagasse is a good substrate for bioethanol production. 4.23g/l of bioethanol was realised with optimization of the fermentation medium

Keywords: Sugarcane bagasse, Bioethanol, Brix, Optimization, Response Surface Methodology.