Sonication of chitin-glucan, preparation of water-soluble fractions and characterization by HPLC

A water-insoluble chitin-glucan complex, isolated from the mycelium of Aspe rgillus niger, was swollen in various aqueous media and treated subsequentl y by high-energy sonication. The concentration of the resulting water-solub le polysaccharide fractions was dependent on the swelling medium, the amoun t of the chitin-glucan complex in the suspension, and on the time of sonica tion. The yields of water-soluble chitin-glucan were within the range 13.6 to 24.4% relative to the mass of the original chitin-glucan. The nitrogen c ontent obtained for the samples of water-soluble chitin-glucan indicated a higher content of chitin (3.45% of nitrogen in high-molecular fraction) tha n in the original water-insoluble chitin-glucan sample (1.8%). The distribu tion of the molecular weights of the water-soluble fractions prepared was d etermined by high-performance liquid chromatography. (C) 2000 Elsevier Scie nce B.V. All rights reserved.