Chitinase and β-N-acetylhexosaminidase from Pycnoporus cinnabarinus

Abstract

Publisher Summary Pycnoporus cinnabarinus , a strain of the chitinase-producing fungi belonging to the basidiomycetes, has produced the chitinolytic enzymes consisting of chitinase and β-N-acetylhexosaminidase. This chapter describes the procedures for the purification of both enzymes. p-Nitrophenyl-β-N-acetylglucosaminide and β-N-acetylgalactosaminide are used as substrates for purification of β-N-acetylhexosaminidase. The assay for chitinase is based on the estimation of reducing sugars produced in the hydrolysis of colloidal chitin according to a modification of Schales' procedure, with N-acetylglucosamine as a reference compound. The enzyme is purified about 15-fold, starting from the precipitate with ammonium sulfate, and thus purified about 45- to 60-fold over the culture filtrate. The chitinase hydrolyzes colloidal chitin and glycol chitin rapidly and powdered chitin very slowly. Acting upon colloidal chitin, and enzyme produces N,N-diacetylchitobiose as the main product accompanied by a slight formation of N-acetylglucosamine.