s to be used for medical and agriculture applications. Moreover, chitosan from shells of shrimps can present antigens in the final product which could cause allergies to the consumer. Thus, although chitosan has been clinically well tolerated, it cannot be recommended to people allergic to crustaceans. These problems may be circumvented by extracting chitosan from different sources.
Nowadays research is focused on extracting pure chitosan from fungal cell wall components. To this aim, N. Nwe et al. studied the bond between chitosan and glucan in fungal cell wall to develop an enzymatic method for the production of very pure chitosan from fungus Gongroella butleri in a high yield (N. Nwe et al. 2010, “Production of fungal chitosan by enzymatic method and applications in plant tissue culture and tissue engineering: eleven years of our progress, present situation and future prospects” Biopolymers, edited by Magdy Elnashar, published: Sep. 28, 2010, chapter 7 pp. 135-162).
EP 1483299 describes a method that allows separating chitin from β-glucans in a controlled way without degradation or transformation of the chitin chains. The method is based on contacting fungal cells of Aspergillus niger with a basic solution, contacting the alkali-insoluble fraction with an acidic solution, whereby obtaining a suspension of acidified alkali-insoluble fraction comprising said cell wall derivatives, and finally contacting it with β-glucanase enzymes to obtain a chitin product or with a chitin deacetylase to obtain a chitosan product.
One application of chitosan is as a dietary antilipidemic supplement where, owing to limited hydrolysis by human digestive enzymes, chitosan passes along the digestive system up to the large intestine practically intact, acting effectively like a dietary fiber. Chitosan is thought to reduce fat absorption from gastrointestinal tract by binding with anionic carboxyl groups of fatty and bile acids, and interferes with emulsification of neutral lipids (i.e., cholesterol, other sterols) by binding t