Extraction and characterization of chitin and chitosan from crustacean by-products: Biological and physicochemical properties

Chitin has been extracted from two Tunisian crustacean species. The obtained chitin was transformed into the more useful soluble chitosan. These products were characterized by their biological activity as antimicrobial and antifungal properties. The tested bacterial strains were Escherichia coli American Type Cell Culture (ATCC) 25922, Pseudomonas aeruginosa ATCC 27950 and Staphylococcus aureus ATCC 25923. Four fungi strains were also tested Candida glabrata, Candida albicans, Candida parapsilensis and Candida kreusei. Squilla chitosan showed a minimum inhibitory concentration (MIC) against the different fungi exceptionally for C. kreusei. Their antioxidant activity was investigated with 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity and inhibition of linoleic acid peroxidation. Parapenaeus longirostris Chitosan showed the highest radical scavenging properties. Chitin and chitosan produced were also characterized with Fourier Transform Infrared Spectroscopy (FTIR). Key words : Antibacterial, antifungal, antioxidant, chitin, chitosan, crustacean.