Evaluation of the Potential of Fungal Acid Proteases of <em>Aspergillus flavus, Aspergillus niger</em> and <em>Penicillium</em> sp. to Produce Shrimp-Waste Protein Hydrolysates with Degraded Antigenic Proteins

Abstract

The waste produced by the shrimp industry can be a great source for the recovery of important bioactive compounds with potential applications in food industry. The present study aimed to characterize extracted proteases of Aspergillus flavus, Aspergillus niger and Penicillium sp. to be utilized as potential sources to produce shrimp waste protein hydrolysates with degraded antigenic proteins. The extracellular fungal acid protease enzymes were extracted under solid substrate fermentation and partially characterized the enzyme activities, concerning the reaction temperature and pH of the reaction medium. Then, the capabilities of extracted fungal protease enzymes to reduce the potential allergens of shrimp waste protein hydrolysates were examined by SDS-PAGE. After incubation of all three fungal species at 37°C and pH 3.0 for 5 days, the highest protease yield, 527.40 μg/mL was achieved from A. flavus. The optimum temperature for A. flavus for the highest protease activity was 45°C, while for other two microorganisms the optimum temperature was 50°C. The optimum pH values for all three proteases were pH 3. According to the SDS-PAGE protein hydrolyzing patterns, the crude acid protease extracted from A. flavus was the best protease to degrade the potential antigenic proteins over the other two acid proteases extracted from A.niger and Penicillium sp., while all three enzymes had shown the potential to reduce the allergenic capacity of shrimp waste proteins through enzymatic hydrolysis.