Preparation of chitooligosaccharides by the enzymatic hydrolysis of chitosan

Chitosan of 80% degree of deacetylation was depolymerised by the cellulase of Aspergillus niger to prepare chitooligosaccharides. MALDI-TOF MS analysis of the enzymatic hydrolyzates indicated that the products were mainly chitooligosaccharides with degree of polymerization (DP) in the 3-11 range. By fractionation of the hydrolyzates with acetone-water, products of DP below 6 and DP above 6 were separated in good yield.