[Chitosan depolymerization by enzymes from hepatopancreas of the crab Paralithodes camtschaticus]

An enzyme preparation was isolated from the Paralithodes camtschaticus hepatopancreas that exhibited chitinase and chitosanase activities. Treatment of chitin and chitosan with this preparation decreased their viscosity-average molecular weights by 96 and 41%, respectively. The chromatographic profiles of the products of chitin and chitosan hydrolysis suggested that the crab hepatopancreas in rich in endochitinases. Enzymatic digestion of chitosan increased its solubility and moderately reduced the extent of its acetylation. A mathematical approach was proposed for calculating the molecular weights of chitosan fractions from weight-average molecular weights determined viscometrically.