Abstract
Several hemicellulases produced from Aspergillus niger van Tieghem sp. were purified and three of them (hemicellulase I, II and III) were found to be xylanase, because these hemicellulases hydrolyzed only xylan and arabinoxylan of various sources.
The mode of action of these enzymes on rice-straw arabinoxylan were studied. Hemicellulase I produced xylose, xylobiose and other xylo-oligosaccharides containing one arabinose residue. Hemicellulase II produced arabinose, xylose and some xylo-oligosaccharides chiefly xylobiose and xylotriose. The main products of hemicellulase III were similar to those of hemicellulase I. But a very small amount of arabinose was also produced by the action of hemicellulase III, indicating a slight difference in the mode of action from hemicellulase I.
From these results, it seemed that hemicellulase I would hydrolyze only xylosidic linkage of arabinoxylan and hemicellulase II would hydrolyze both xylosidic and arabinosidic linkages. Hemicellulase III might mainly hydrolyze xylosidic linkage but also hydrolyze some particular arabinosidic linkage of arabinoxylan.
