title: Chitin extraction from shrimp shell using enzymatic treatment. Antitumor, antioxidant and antimicrobial activities of chitosan.
abstract: Chitin was recovered through enzymatic deproteinization of the shrimp processing by-products. Different microbial and fish viscera proteases were tested for their deproteinization efficiency. High levels of protein removal of about 77±3% and 78±2% were recorded using Bacillus mojavensis A21 and Balistes capriscus proteases, respectively, after 3h of hydrolysis at 45°C using an enzyme/substrate ratio of 20U/mg. Therefore, these two crude proteases were used separately for chitin extraction and then chitosan preparation by N-deacetylation. Chitin and chitosan samples were then characterized by 13 Cross polarization magic angle spinning nuclear magnetic resonance (CP/MAS)-NMR spectroscopy and compared to samples prepared through chemical deproteinization. All chitins and chitosans showed identical spectra. Chitosans prepared through enzymatic deproteinization have practically the same acetylation degree but higher molecular weights compared to that obtained through chemical process. Antimicobial, antioxidant and antitumoral activitities of chitosan-M obtained by treatment with A21 proteases and chitosan-C obtained by alkaline treatment were investigated. Results showed that both chitosans inhibited the growth of most Gram-negative, Gram-positive bacteria and fungi tested. Furthermore, both chitosans exhibited antioxidant and antitumor activities which was dependent on the molecular weight.
authors.affiliation: Laboratory of Enzyme Engineering and Microbiology, University of Sfax, National School of Engineering, PO Box 1173-3038 Sfax, Tunisia. Electronic address: islem.younes@gmail.com.
authors.forename: Islem
authors.initials: I
authors.lastname: Younes
authors.affiliation: Laboratory of Enzyme Engineering and Microbiology, University of Sfax, National School of Engineering, PO Box 1173-3038 Sfax, Tunisia.
authors.forename: Sawssen
authors.initials: S
authors.lastname: Hajji
authors.affiliation: AGing Imaging Modeling, CNRS FRE 3405, Université Joseph Fourier, EPHE, Grenoble, France.
authors.forename: Véronique
authors.initials: V
authors.lastname: Frachet
authors.affiliation: Biomaterials Applications, 6, rue Lesdiguières 38000 Grenoble, France.
authors.forename: Marguerite
authors.initials: M
authors.lastname: Rinaudo
authors.affiliation: Laboratory of Enzyme Engineering and Microbiology, University of Sfax, National School of Engineering, PO Box 1173-3038 Sfax, Tunisia.
authors.forename: Kemel
authors.initials: K
authors.lastname: Jellouli
authors.affiliation: Laboratory of Enzyme Engineering and Microbiology, University of Sfax, National School of Engineering, PO Box 1173-3038 Sfax, Tunisia.
authors.forename: Moncef
authors.initials: M
authors.lastname: Nasri
mesh_terms: D060105:Animal Shells / Q000737:chemistry*; D000818:Animals; D000890:Anti-Infective Agents / Q000302:isolation & purification / Q000378:metabolism / Q000494:pharmacology; D000970:Antineoplastic Agents / Q000302:isolation & purification / Q000378:metabolism / Q000494:pharmacology; D000975:Antioxidants / Q000302:isolation & purification / Q000378:metabolism / Q000494:pharmacology; D001419:Bacteria / Q000187:drug effects; D045744:Cell Line, Tumor; D048271:Chitosan / Q000302:isolation & purification* / Q000378:metabolism / Q000494:pharmacology*; D003445:Crustacea / Q000737:chemistry*; D005658:Fungi / Q000187:drug effects; D051379:Mice; D008903:Minerals / Q000302:isolation & purification; D010447:Peptide Hydrolases / Q000378:metabolism*
chemical_list: D000890:Anti-Infective Agents; D000970:Antineoplastic Agents; D000975:Antioxidants; D008903:Minerals; D048271:Chitosan; D010447:Peptide Hydrolases
keywords: Antimicrobial; Antioxidant; Antitumor; Chitin; Chitosan