Full Length Research Paper

Production of bio-ethanol from corncobs using Aspergillus niger and Saccharomyces cerevisae in simultaneous saccharification and fermentation

H. D. Zakpaa, E. E. Mak-Mensah* and F. S. Johnson

Department of Biochemistry and Biotechnology, School of Biosciences, KNUST, Kumasi, Ghana.

*Corresponding author. E-mail: eemakmensah@gmail.com. Tel: +233-246-247811.

Accepted 17 April, 2009

Maize is the most abundant cereal grown in Ghana and is accompanied by enormous amount of agrowastes of which corncobs form 30%. This agrowaste which is currently under utilized was used to produce bio-ethanol. Aspergillus niger isolated from soil sampled from Ejura farms was used to hydrolyze the corncobs into simple sugars. Filtrate obtained from corncobs broth fermented by A. niger was used as crude enzyme in optimization tests on corncobs powder suspended in 50 mM citrate buffer pH 5.0. Optimum temperature, pH and substrate concentration for saccharification were 40^oC, 4.0 and 6% respectively. Saccharomyces cerevisae was added to A. niger filtrate to cause fermentation of the corncobs. The highest ethanol concentration of 0.64 g/l was recorded over the 24 h fermentation period.

Key words: Aspergillus niger, saccharification, simultaneous saccharification, fermmentation.