The aim of this research is to compare the potential of sweet potato and cocoyam peels (non-edible waste material) for bioethanol production using sequential monocultures of Aspergillus niger and Saccharomyces cerevisiae and co-cultures of Aspergillus niger and Saccharomyces cerevisiae. Each sample was dried and ground; and was subjected to heat pretreatment. Direct fermentation of pretreated sweet potato and cocoyam peels to ethanol by sequential mono-cultures of Aspergillus niger and Saccharomyces cerevisiae and co-cultures of Aspergillus niger and Saccharomyces cerevisiae was determined for 7 days during which reducing sugar yield, amylolytic activity rate, residual starch and ethanol yield were determined. Result obtained showed residual starch (16.30±0.01gg/ml - 4.42±0.02a g/ml) and reducing sugar (27.90±0.03c - 4.21±0.01a g/ml) yield decreased as fermentation progresses. amylolytic activity rate (0.00±0.00a to 150.50±0.04d) and ethanol yields (0.00±0.00a - 8.45±0.02gml/100ml) increased several-fold in co-cultures and mono-cultures with sweet potato monoculture fermentation having the highest bioethanol yield (8.45±0.02gml/100ml) while cocoyam co-culture fermentation has the lowest bioethanol yield (0.00±0.00aml/100ml). Cocoyam and sweet potato peels can be used to produce bioethanol.

Keywords: Bioethanol, cocoyam, sweet potato, Aspergillus niger, Saccharomyces cerevisiae