Abstract:

Xylanase Shearzyme 500L was used to hydrolyze bagasse xylan for preparing xylooligosaccharide. DNS was used to determine the contents of total sugar and reducing sugar in hydrolysates and HPLC was used to determine the compositions of hydrolysates. The optimal hydrolysis conditions were substrate concentration of 3 g/100 mL, hydrolysis pH of 5.0, hydrolysis temperature of 60 ℃, enzyme addition amount of 50 U/g and hydrolysis time of 24 h. Under the optimal hydrolysis conditions, the hydrolysis rate of bagasse xylan was approximately 63.1%, and the xylooligosaccharide in hydrolysates was up to 81.5%, which included 54.8% xylobiose and 26.7% xylotriose. Xylotriose could be hydrolyzed to xylobiose and xylose by xylanase shearzyme 500 L, but xylobiose could not be hydrolyzed to xyloses. The by-product xylose could also obviously suppress the activity of xylanase shearzyme 500 L and reduce the hydrolysis rate of bagasse xylan.