Bioconversion of cassava starch to ethanol in a simultaneous saccharification and fermentation process by co-cultures of Aspergillus niger and Saccharomyces cerevisiae.

Abstract

Ethanol production by co-cultures of A. niger (GS4) and S. cerevisiae (BK6) was studied using cassava starch as substrate. At 1% substrate concentration ethanol yield was 0.35g/100ml while the ethanol concentration increased to a maximum of 3.60g/100ml at 8% substrate concentration. When the culture conditions were optimized, the ethanol yield further increased to 4.30g/100ml at a temperature of 35oC, pH 5.0, 300rpm agitation rate and reduced fermentation period of 4 days.

Keywords: A. niger, S. cerevisiae, Fermentation, Ethanol, Cell dry
weight, Residual sugar