title: Solvent-stable digestive alkaline proteinases from striped seabream (Lithognathus mormyrus) viscera: characteristics, application in the deproteinization of shrimp waste, and evaluation in laundry commercial detergents.
abstract: Alkaline proteases from the viscera of the striped seabream (Lithognathus mormyrus) were extracted and characterized. Interestingly, the crude enzyme was active over a wide range of pH from 6.0 to 11.0, with an optimum pH at the range of 8.0-10.0. In addition, the crude protease was stable over a broad pH range (5.0-12.0). The optimum temperature for enzyme activity was 50 °C. The crude alkaline proteases showed stability towards various surfactants and bleach agents and compatibility with some commercial detergents. It was stable towards several organic solvents and retained more than 50% of its original activity after 30 days of incubation at 30 °C in the presence of 25% (v/v) dimethyl sulfoxide, N,N-dimethylformamide, diethyl ether, and hexane. The crude enzyme extract was also tested for shrimp waste deproteinization in the preparation of chitin. The protein removal with a ratio enzyme/substrate of 10 was about 79%.
authors.affiliation: Laboratoire de Génie Enzymatique et de Microbiologie-Ecole Nationale d'Ingénieurs de Sfax, B.P. 1173, 3038 Sfax, Tunisia.
authors.forename: Nedra El-Hadj
authors.initials: Nel-H
authors.lastname: Ali
authors.forename: Noomen
authors.initials: N
authors.lastname: Hmidet
authors.forename: Olfa
authors.initials: O
authors.lastname: Ghorbel-Bellaaj
authors.forename: Nahed
authors.initials: N
authors.lastname: Fakhfakh-Zouari
authors.forename: Ali
authors.initials: A
authors.lastname: Bougatef
authors.forename: Moncef
authors.initials: M
authors.lastname: Nasri
mesh_terms: D000818:Animals; D001426:Bacterial Proteins / Q000737:chemistry / Q000378:metabolism*; D001709:Biotechnology / Q000379:methods*; D002686:Chitin / Q000096:biosynthesis; D033364:Decapoda / Q000378:metabolism; D003902:Detergents / Q000737:chemistry / Q000378:metabolism*; D004591:Electrophoresis, Polyacrylamide Gel; D010450:Endopeptidases / Q000737:chemistry / Q000378:metabolism*; D004795:Enzyme Stability; D029941:Fish Proteins / Q000378:metabolism*; D006863:Hydrogen-Ion Concentration; D059027:Recycling / Q000379:methods*; D021541:Sea Bream / Q000378:metabolism*; D012997:Solvents / Q000737:chemistry; D013696:Temperature; D014781:Viscera / Q000201:enzymology*; D014866:Waste Products
chemical_list: D001426:Bacterial Proteins; D003902:Detergents; D029941:Fish Proteins; D012997:Solvents; D014866:Waste Products; D002686:Chitin; D010450:Endopeptidases; C087822:alkaline protease