Two Routes to Produce Chitosan from Agaricus bisporus

Abstract

Two methods were used to produce chitosan by deacetylation of chitin which was extracted from <i>Agaricus bisporus</i> stipes. The first one gives chitosan 1 with low yield of 2.5%, degree of acetylation (DA) of 4%, molecular weight (MW) of 2.973 × 10⁵ (g/mol). The second route produces chitosan 2 with higher yield of 41%, degree of acetylation (DA) of 17.23%, molecular weight (MW) of 2.939 × 10⁵ (g/mol). Both chitosans were characterized by XRD, FTIR, ¹ H-NMR spectroscopy nuclear magnetic resonance of proton. The molecular weight (M_W) was determined by size exclusion chromatography (SEC). Thermal analysis shows that both chitosans have moisture content lower than 10%. However chitosan 2 has the less ash % which is the quality grade for chitosan medical applications. Accordingly, fungal chitosan 2 could have potential medical and agricultural applications.