Effects of washing, milling and loading enzymes on the enzymatic hydrolysis of a steam pretreated sugarcane bagasse

Enzymatic hydrolysis of steam pretreated sugarcane bagasse was performed to investigate the production of glucose and xylose. A blend of industrial enzymes (Novozymes) was used. The enzymes were used either without having been washed or having been washed with water or 1% aqueous NaOH solution. The influence of the size of sugarcane bagasse and the proportion of the enzymatic cocktail, which was composed of endoglucanases/cellobiohydrolases (Celluclast 1.5L) and β-glucosidase (Novozym 188) cellulases mixtures, was investigated. The tests were performed at a temperature of 50 °C and at a pH of 4.8 during a period of 72 h. The assays that were conducted with a pretreated sugarcane bagasse that was washed with a 1% aqueous NaOH solution without milling led to the largest amounts of glucose after 72 h, which was independent of the proportions of enzymes used in experiments with the smallest amounts of enzymes. The largest amount of xylose was obtained with a pretreated sugarcane bagasse that was not washed.

Research highlights▶ Milling an unwashed sugarcane bagasse had no influence on the amounts of sugars obtained after hydrolysis. ▶ Washing steam pretreated bagasse with water decreases the amount of glucose by hydrolysis. ▶ If the bagasse is milled, washing with water no had influence in the amount of glucose by hydrolysis. ▶ Washing steam pretreated bagasse with NaOH 1% resulted in best amounts of glucose after hydrolysis operations.