Chitosan (poly b-(1-4)N-acetyl-d-glucosamine), a
deacetylated form of chitin, is a natural antimicrobial
compound. On the one hand it can be obtained from
crustacean shells (crabs, shrimp and crayfishes) either by
chemical or microbiological processes and on the other
hand it can be produced by some fungi (Aspergillus
niger, Mucor rouxii, Penecillium notatum) (Tan et al.,
1996; Knorr, 1984).