Rapid extraction of high-quality chitosan from Mycelia of Absidia Glauca

A rapid two-step extraction method for high quality fungal chitosan from Absidia glauca was developed. Fungal mycelia are autoclaved in a 1M caustic soda solution at 121C for 15 min. The alkali-insoluble-materials obtained are then further autoclaved for 15 min in a 2% aqueous acetic acid solution. There was a relatively low degree of N-deacetylation and chain degradation of the chitosan. The integrity of the product can be attributed to the mild acid used, the short reaction time and the steam environment. When the acid extraction step was carried out in a 1M hydrochloric acid solution under the same conditions, the highest degree of extraction was attained, albeit with some degree of chain degradation. When compared to existing extraction methods, our procedure is efficient, time-and labor-saving, and can handle both small and large samples. In addition, chitosan obtained by this method is essentially free of impurities.