Preparation of N,N'-diacetylchitobiose from chitin by enzymatic hydrolysis

Abstract

Two types of enzymes, cellulase Ac from Acremonium cellulolyticus and Chi 60 from Serratia sp, were studied for a preparation of N,N' -Diacetylchitobiose from chitin. The optimum conditions for both enzymes to hydrolyzed chitin were investigated in this work. In study for the optimum condition of cellulase Ac, powder chitin and fibrous chitin were used as the substrates. The difference optimum conditions of both substrates were chitin concentration and enzyme concentration. The (G1cNAc)₂/GIcNAc mole ratio can be improved from 1 to over 3 by using the enzyme affinity technique, indicating that cellulase Ac contained both chitinase and β- N-acetylhexosaminidase. For Chi 60, only fibrous chitin was used as a substrate. At lower concentration of Chi 60 (< 30 mU/mL), the chitinolytic product was only (G1cNAc)₂ but at higher concentration of the enzyme, both (G1cNAc)₂ and GIcNAc were observed. The enzyme affinity technique cannot be used to improve the (G1cNAc)₂/G1cNAc mole ratio for Chi 60 indicating that this enzyme consists of only one enzyme which had both endo- and exo-chitinolytic activities.