Contribution à l’extraction de la chitine et de chitosane à partir d’un produit aquacole Soutenue publiquement le /06/2023 Devant le Jury Président Dr. BELBACHIR. N MCA U. Mostaganem Encadreur Dr. OULHIZ. A MCB U. Mostaganem Examinateur Dr. BENZAIT. H MCB U. Mostaganem Année universitaire 2022/2023 Université Abdelhamid Ibn Badis-Mostaganem Faculté des Sciences de la Nature et de la Vie République Algérienne Démocratique et Populaire جامعة عبد الحميد بن باديس مستغانم كلية علوم الطبيعة و الحياة

Abstract

This work is part of the extraction of chitin and chitosan from the scales of common carp (Cyprinus carpio). To then study the most important characteristics of chitosan (solubilization, ash composition, degree of acetylation and deacetylation) as well as the antifungal and antibacterial power of chitosan extracted from common carp scales by two different methods (chemical treatment and enzymatic treatment of chitin). We noticed that the method of chemical extraction of chitin is better than the second method of extraction of chitin (enzymatic), concerning the mass yield of chitosan obtained by deacetylation of chitin (14.46 and 24.75% respectively) as well as the degree of deacetylation (89.53 and 80.73% respectively) and contrary for the degree of acetylation (10.47 and 19.27%). Although the DD rate is greater than 80%, the solubilization of the two chitosan is very low (less than 50%). And the results of the antimicrobial activity of the two chitosan obtained, show a resistance of the bacterium Gram (-) E. coli in the presence of chitosan. On the other hand, the two chitosan have an inhibitory action against the growth of the strains studied, with a high sensitivity especially for Condida albican, Aspergillus brasiliensis and the Gram (+) bacterium Listiria monocytogenes.