Most nations, whether economically advanced or at different stages of development are faced with the problem of disposal and treatment of wastes. Wastes could be treated in several ways (e.g. by reducing its bulk or by recovering and reprocessing it into useful substance) to meet sanitary standards. Ethanol fermented from renewable sources for fuel or fuel additives are known as bio-ethanol. In Nigeria, many food crops have been specifically grown for the production of bio-ethanol. However, bio-ethanol production from waste materials removed from food crops is very rare. In the present study, food crop wastes such as yam, potato and sweet potato peels, which are in abundance and do not interfere with food security were subjected to simultaneous saccharification and fermentation for 7days by co-culture of Aspergillus niger and Saccharomyces cerevisiae. Biomass yield, cell dry weight, reducing sugar concentration and the ethanol yield were determined at 24 hours interval. The results of the study showed that after 7 days of fermentation, sweet potato peels had the highest biomass yield of 4.65 (OD), followed by yam peels 3.50 (OD), while potato peels had the least 2.38 (OD). The microbial cell dry weights obtained from the wastes materials ranged between 6.04 -9.50 mg/cm~3, while their reducing sugar concentrations ranged between 0.10 - 0.72 mg/cm~3. The optimal ethanol yields were 10.89% v/v, 9.40 % v/v and 6.00% v/v for sweet potato, yam and potato peels respectively. These indicate that sweet potato and yam peels ethanol yields were significantly higher (P<0.05) than potato peel ethanol yield. The findings of this study suggest that food crop wastes that contain fermentable sugars can no longer be discarded into our environment, but should be converted to useful products like bio-ethanol that can serve as alternative energy source.
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