Production of high-concentration fermentable sugars from lignocellulosic biomass by using high solids fed-batch enzymatic hydrolysis

Abstract

The synergy of multiple lignocellulolytic enzymes for lignocellulosic biomass saccharification at high substrate loading to obtain high-concentration fermentable sugar is of great economic interest for industrial biorefineries. In this study, the mixture of cellulase, β-glucosidase, hemicellulose, and pectinase was optimized for hydrolysis of different cellulosic feedstocks at different substrate concentrations. It was found that the enzyme combination of 43.8% cellulase, 41.8% hemicellulase, 14.4% pectinase was more suitable for high-concentration alkaline hydrogen peroxide pretreated corncob hydrolysis. The optimized enzyme mixture was then applied to fed-batch enzymatic hydrolysis. The cumulative solid loading was 40% (w / w). After 48 h of hydrolysis, the glucose and xylose concentration reached 110.47 g/L and 61.88 g/L, respectively. The fermentable sugar productivity was up to 3.6 g/L/h. In addition, the enzyme components for high-concentration substrate hydrolysis were optimized. The substrate concentration was increased by fed-batch hydrolysis, and the high-concentration fermentable sugar was obtained in a shorter time.