Enhancement of Enzymatic Hydrolysis of Sugarcane Bagasse by the Combination of Delignification Pretreatment and Polysorbate 80

Delignification pretreatment with alkali under various conditions (25–160 °C for 1–12 h) or sodium chlorite at 75 °C for 4 h was applied to improve the enzymatic digestibility of sugarcane bagasse by removing hemicellulose and lignin. Compared with the elimination of hemicellulose, delignification contributed more in achieving a higher glucose yield. In addition, the characterization of untreated and pretreated sugarcane bagasse was conducted to determine the influence of hemicellulose and lignin degradation on subsequent enzymatic digestibility. Furthermore, Polysorbate 80 was added to reduce the enzyme loading, shorten the hydrolysis time, and enhance the efficiency of enzymatic hydrolysis, suggesting that the glucose yield of 92.2% was obtained with enzyme loading of 5 FPU/g substrate. However, the increased yield of glucose with Polysorbate 80 occurred with an increased lignin content and a reduction of enzyme loading, and the yield decreased sharply as the hydrolysis time was prolonged from 6 h to 24 h.