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%.

<i>Arthrobacter arilaitensis</i> Re117 as a Source of Solvent-Stable Proteases: Production, Characteristics, Potential Application in the Deproteinization of Shrimp Wastes and Evaluation in Liquid Laundry Commercial Detergents

“…The inhibition caused by this ion suggests the relevance of sulfhydryl residues for the catalytic action of most proteases [24]. The effects of Cu 2+ and Mn 2+ (respectively, 71% and 78%) proved to be similar to those recorded for L. mormyrus enzyme (respectively, 82% and 69%) [25] …”

“…El-Hadj Ali et al [25] showed that the half-lives of L. mormyrus proteases were about 18 and 17 days in the presence of methanol and acetone, respectively. Interestingly, the stability of the crude protease was highly enhanced by DMSO, DMF, diethyl ether and hexane; the half-lives of the enzyme in the presence of these solvents were more than 30 days.…”

Zebra blenny (Salaria basilisca) viscera as a source of solvent-stable proteases: characteristics, potential application in the deproteinization of shrimp wastes and evaluation in liquid laundry commercial detergents

“…The inhibition caused by this ion suggests the relevance of sulfhydryl residues for the catalytic action of most proteases (Bezerra et al 2005). The effects of Cu 2+ and Mn 2+ (respectively, 4 % and 37.5 %) proved to be stronger than those recorded for L. mormyrus enzyme (respectively, 82 % and 69 %) (El-Hadj Ali et al 2011 …”

Digestive alkaline proteinases from Serranus scriba viscera: Characteristics, application in the extraction of carotenoproteins from shrimp waste, and evaluation in laundry commercial detergents

“…Today, there is an increasing demand for fish proteolytic enzymes. In fact, fish viscera, one of the most important by-products of fishing industry, is known to be an important source of enzymes that can be used for several industrial applications, due to their unique properties, including high activity over a wide range of pH and temperature conditions (Jellouli et al, 2009;El Hadj-Ali et al, 2011;Nasri et al, 2012) and high activity at relatively low concentration (Haard, 1998). Considering the specific characteristics of these enzymes, fish processing by-products are currently used for enzyme extraction.…”