Utilization of millet and guinea corn husks for bioethanol production

Abstract

In this study, the rumen of ruminant animals served as a source for isolation of bacteria used in the hydrolysis of millet husks and guinea corn husks prior to fermentation. The isolates were characterized and identified as Bacillus firmus, Bacillus circulans, Escherichia coli, Proteus rettgerii, Paenibacillus macerans and Serratia marcescens. Zymomonas mobilis and Saccharomyces cerevisiae isolated from a previous study were used as the fermentative organisms. The production of bioethanol was done by hydrolysis and fermentation. The results obtained revealed that highest yield of reducing sugar of (4.10%) was obtained from guinea corn husk while the reducing sugar yield of millet husk was 3.21%. The highest concentration of bioethanol of (2.33%) was produced using the combination of S. cerevisiae and Z. mobilis for fermentation of guineacorn husks. Similarly, the lowest concentration of 0.79% was obtained when Z. mobilis was used on hydrolysates from millet husk. The results of the study revealed the potentiality of the two agro wastes to produce bioethanol. However, guinea corn husk is more promising than millet husk as it produces more bioethanol and can be used for large scale production.