Bioconversion of chitin to chitosan: purification and characterization of chitin deacetylase from Mucor rouxii.

Abstract

Chitin deacetylase, the enzyme that catalyzes the hydrolysis of acetamido groups of N-acetylglucosamine in chitin, has been purified to homogeneity from mycelial extracts of the fungus Mucor rouxii and further characterized. The enzyme exhibits a low pI (-3). Its apparent molecular mass was determined to be =75 kDa by sodium dodecyl sulfate/polyacrylamide gel electrophoresis and -80 kDa by size-exclusion chromatography, suggesting that the enzyme exists as a monomer. Carbohydrate analysis of purified chitin deacetylase revealed that the enzyme is a high-mannose glycoprotein and that its carbohydrate content is -30% by weight. Chitin deacetylase is active on several chitinous substrates and chitin derivatives. The enzyme requires at least four N-acetylglucosamine residues (chitotetraose) for catalysis, and it is inhibited by carboxylic acids, particularly acetic acid. When glycol chitin (a water-soluble chitin derivative) was used as substrate, the optimum temperature for enzyme activity was determined to be -.50°C and the optimum pH was -4.5.

Yeast ascospore wall assembly requires two chitin deacetylase isozymes

“…In vitro experiments suggested di¡erent speci¢c-ity of chitin deacetylases on chitin oligosaccharides [13,14]. CDA from the fungus M. rouxii [14], which is inhibited by acetic acid [3], is able to deacetylate chitin oligosaccharides with a degree of polymerization higher than 3 and it fully deacetylates only (GlnNAc) 4 and (GlnNAc) 5 . C. lindemuthianum CDA, on the other hand, which is not inhibited by acetic acid [4], is able to deacetylate (GlnNAc) 2 and fully deacetylates (GlnNAc) 3 to (GlnNAc) 5 [13].…”

“…The activity of only some deacetylases [3,4,10,11] is inhibited by acetic acid. We therefore measured the activity of both CDAs by adding increasing concentrations of acetic acid in the reaction mixture (Fig.…”

“…[1,2] Chitin deacetylase (CDA) is the enzyme that catalyzes the conversion of chitin to chitosan by deacetylation of N-acetyl-D-glucosamine residues. So far, CDA enzymes have been isolated from the fungi Mucor rouxii and Colletotrichum lindemuthianum [3,4] and genes encoding CDA have been studied in M. rouxii and Saccharomyces cerevisiae [5,6].…”

A HighlyN-Glycosylated Chitin Deacetylase Derived from a Novel Strain ofMortierellasp. DY-52

“…2) The members of this family share a well-conserved region in their primary structure, which has been designated the ''NodB homology domain'' or the ''polysaccharide deacetylase domain.'' CDAs have been purified and characterized from several fungal species, including Mucor rouxii, 3) Colletotrichum lindemuthianum, 4,5) and Saccharomyces cerevisiae. 6) Among these, a few CDAs have been confirmed to be glycoprotein, with carbohydrate contents of 18-67% by weight.…”

Extracellular chitin deacetylase production in solid state fermentation by native soil isolates of Penicillium monoverticillium and Fusarium oxysporum

“…oxysporum CFR 8 in solid state fermentation using commercial wheat bran (CWB) and shrimp processing by-products (SPP) media Not much information regarding the fermentation processes and yield of chitin deacetylase is available except few reports (Kim et al 2008;Zhou et al 2010;Suresh et al 2011a). Most of the works on chitin deacetylase were carried out from the viewpoint of their purification and characterization, mode of action on substrate and their substrate specificity (Kauss and Bauch 1988;Kafetzopoulos et al 1993;Tsigos and Bouriotis 1995;Tokuyasu et al 1996;Tsigos et al 1999;Kadokura et al 2006). Recently some researchers have studied the production of microbial extracellular chitin deacetylase by different fermentation methods due to its potential in industry for the preparation of chitosan with unique quality (Kim et al 2008;Zhou et al 2010;Suresh et al 2011a).…”