Ultrasonic depolymerization of the chitin-glucan isolated from Aspergillusniger

By means of ultrasonication two fractions of the carboxymethylated chitin-g lucan complex isolated from the cell walls of the filamentous fungus Asperg illus niger were obtained. Elemental analysis as well as C-13 NMR investiga tion of the high-molecular weight (M-w 680 kDa) and low-molecular weight (M -w 75 kDa) fractions revealed their essentially different chitin content. H PLC analysis of the fractions produced by ultrasonic treatment of different duration, combined with nitrogen assay showed steadily increasing chitin c ontent in the faster eluted fraction that allows one to suggest the differe nt susceptibility of the two components of the chitin-glucan complex to the ultrasonication. (C) 1999 Elsevier Science B.V. All rights reserved.