High contents of cellulose and hemicellulose of corncob waste makes it suitable as a raw material for sugar saccharification that can be used as sugar source for bioethanol fermentation. However, the presence of lignin inhibits the complete sugar conversion, necessitating pretreatment of the corncob material. Therefore, our study aimed to introduce a new pretreatment method for corncob to minimize lignin contents, hydrolyze it using an enzyme cocktail, and ferment it to bioethanol. Firstly, we studied pretreatment of corncob powder to minimize lignin interference using various reagents like 2% H2SO4, 2% NaOH, 2% H2SO4 – 2% NaOH, and 15% NH4OH, which revealed that 15% NH4OH was the most efficient reagent. Then, several enzyme cocktails consisting of cellulase, xylanase, and xylose isomerase, isolated from microbes collected in Indonesia, in ratios of 1:1:1, 2:1:1, 1:2:1, and 1:1:2 were subjected to the pretreated corncob material. We found that hydrolysis with the enzyme cocktails produced significant amounts of reducing sugars, and 1:1:1 enzyme cocktail produced the highest amounts with amazing capability to ferment to bioethanol.
- Xylose isomerase