Recovery of alkaline proteinases from fisheries wastes: biochemical characterization and applications

Abstract

Fish visceral waste, which is normally discarded, is considered one of the richestsources of proteinases with potential biotechnological applications. For this reason,alkaline proteinases from viscera of Argentine hake Merluccius hubbsi, Brazilian flatheadPercophis brasiliensis, Brazilian codling Urophycis brasiliensis, and stripped weakfishCynoscion guatucupa were characterized. Individuals were caught by acommercial fleet off the coast of the Argentinean Sea. The intestine and pyloric caecawere dissected out and then minced and triturated with distilled water. The proteinaseactivity of P. brasiliensis extracts was enhanced by all the ions tested (Mn2+, K+,Na+, Ca+2) while the enzymes of the other species were stable in the presence ofthose ions, retaining more than 60% of their enzymatic activity. Alkaline proteinasesof all species showed extreme stability to 5% v/v surfactants at 60 min (Sodiumdodecyl sulfate, Triton X-100, Tween 20, Tween 80), and relative stability toward an6% v/v oxidizing agent (H2O2) and organic solvents 80% (acetone, isopropanol, methanol,ethanol). The enzyme extracts were incubated for 60 min with these compounds.Interestingly, alkaline proteinases from all species were compatible with thecommercial detergents (Ala, Skip, and Ace). These results demonstrate that proteinasesrecovered from a no-cost sample such as fishery residues can be used for industrialapplications, such as detergent formulations.