Extraction of α-, β- and γ-chitosan from Crab (Portunus segnis), Sepia (Sepia pharaonis) and Fungi (Aspergillus niger) respectively and comparison of their antimicrobial activities

Three types of chitin as α (exoskeleton of crustaceans), β (cuttlebone of cephalopods) and γ (some fungal cell wall) exists in nature. Chitosan is the best derivative of chitin, which has different biological activity. In this study α, β and γ-chitosan was extracted from Portunus segnis exoskeleton, Sepia pharonis cuttlebone and Aspergillus niger cell wall, respectively. Samples of crab and sepia in summer of 1393 from Bandar Abbas coastal water were and A. niger (PTCC 5223) was obtained from the Iranian Research Organization for Science and Tech� capturedd nology (IROST). Antimicrobial activities of three types of chitosan were explored against 9 bacterial and 2 fungal strains using disc diffusion method. Crab chitosan was higher than cuttlefish and fungal chitosan calculated. On average α chitosan and γ chitosan revealed biggest and lowest antimicrobial activities, respectively. However, the higher antimicrobial activity was recorded by fungal chitosan against Candida albicans (18.53 ± 0.94 mm). Antibacterial properties of chitosan extracts were more than their antifungal properties. Gram negative bacteria were sensitive to three types of chitosan as well as gram positive bacteria. According to observed results, three .types of chitosan have a good antimicrobial activity on some pathogens that required further investigation

کلیدواژه ها:

biological compounds ، crustaceans ، mollusks ، microorganisms