Abstract
Bio-ethanol is considered as an important renewable fuel to partly replace fossil-derived fuels. In this study, bioethanol production, which includes cellulase production, saccharification of the cellulose content of sesame seed residue, and ethanol production, was investigated. Out of the hundreds of cellulase-producing bacterial strains isolated from sesame seed residue during this study, the B isolate was found to have the highest cellulase enzyme production. This isolate was identified as Bacillus cereus by 16S rRNA sequencing. The effects of different growth parameters, including inoculum concentration, incubation time, temperature, pH, and carbon and nitrogen sources, were investigated to optimize the growth conditions of the bacterifum. The maximum cellulase activity was achieved with an inoculum concentration of 3% after 48 h in a basal medium at a pH of 7 and an incubation temperature of 35 degrees C. The best nitrogen and carbon sources were yeast extract and sesame seed residue, respectively. The results showed the liberation of 2.3 g/L of reducing sugar by the dinitrosalicylic acid method. This total reducing sugar produced 15 g/L of ethanol after 48 h when Saccharomyces cerevisiae was used as a fermentation agent. Hence, bioethanol was successfully produced from the cellulose of sesame seed residue using the cellulase enzyme from B. cereus.