Chitosan has a broad-spectrum antimicrobial activity against both Gram-positive and Gram-negative bacteria. Also, antimicrobial activity is attributed to chitosan when the amino groups are in cationic form, which means that antimicrobial activity of chitosan is higher at low pH. Due to solubility of chitosan in acidic aqueous medium, various applications at industrial area can be found for it its solubility is due to the degree of acetylation, molecular weight, and distribution of the acetyl and amino groups along the chain.

Also, the chitin can be extracted from various sources to be converted to chitosan by different degree of dacetaylation during using different concentration of NaOH. Chemical structures of chitin and chitosan.Ĭrab, shrimp and lobster, as well as in the exoskeleton of marine zooplankton spp., including coral and jellyfishes. Since it is non-toxic and presents excellent biological properties such as biodegradation in the human body, immunological, antibacterial, and wound-healing activity, as shown in (Scheme 1), chitosan has been widely used in food and pharmaceutical processes and in medical and agricultural drugs.

The alkaline deacetylation of chitin produces a very useful material chitosan, which known as a copolymer of (1 → 4) linked 2-amino-2-deoxy-D-gluco-pyranose units, and also it is found naturally in some fungal cell walls.

A white hard polysaccharide chitin, which known as 2-acetamido-2-deoxy-D-gluco-pyranose units through (1 → 4) linkage, is extracted from the crustacean’s exoskeletons and also from crabs and shrimps.

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