Microbial bioethanol production from locally sourced corncobs through saccharification and fermentation using Aspergillus niger and Saccharomyces cerevisiae

Abstract


 The utilization of agricultural residues, specifically corncobs, as a renewable feedstock for bioethanol production holds promise in sustainable energy generation. This study investigates the feasibility of microbial bioethanol production from locally sourced corncobs through co-digestion involving Aspergillus niger and Saccharomyces cerevisiae. The process involved washing the corncobs, grinding them, and then hydrolyzing the corncob flour with cultured Aspergillus niger. The resulting sugar syrup was then fermented with Saccharomyces cerevisiae to produce ethanol. The process was optimized to obtain the highest ethanol yield. The results indicated that the process developed achieved a maximum ethanol yield of 33.2, 36.7, and 45.5% from the triplicate digesters used with a percentage purity in the range of 62.06% to 87.69% and a mean volume of ethanol recovery of 145 mL per 400 mL of the fermented product. This yield was obtained when the temperature of the hydrolysis using inoculum and saccharification were maintained at 27 °C. Additionally, the optimal substrate concentration for maximum ethanol yield was found to be 50 % (w/v). The study demonstrates the potential of corncobs obtained from local mashing as a source of fermentable sugars for the microbial production of bioethanol. Additionally, the results provide a basis for the development of an efficient and economically feasible process for production of bioethanol from corncobs obtained from local mashing.