Effect of ultrasonic treatment on the molecular weight of carboxymethylated chitin-glucan complex from Aspergillus niger.

ABSTRACT

Different factors affecting the efficiency of the ultrasonic depolymerization of the high-molecular-weight carboxymethylated chitin-glucan prepared from the fungal mycelium of Aspergillus niger have been investigated. The influence of the following parameters was examined concentration of the chitin-glucan complex, duration of ultrasonic irradiation, reaction temperature and volume of the ultrasonicated solution. The optimized conditions for the efficient ultrasonic depolymerization include polysaccharide concentration--0.2 mg ml-1; volume of the sonicated solution--25 ml; duration of the sonication--10 min; and constant cooling of the sonicated sample in an ice-water bath.