F. Namjou - Department of Fisheries, Faculty of Animal Sciences and Fisheries, Sari Agricultural Sciences and Natural Resources University (SANRU), Sari, Iran
S. Yeganeh - Department of Fisheries, Faculty of Animal Sciences and Fisheries, Sari Agricultural Sciences and Natural Resources University (SANRU), Sari, Iran
R. Madani - Department of Proteomics & Biochemistry section Biotechnology, Razi Vaccine and Serum Research Institute, Agricultural Research, Education and Extension Organization (AREEO), Karaj, Iran
H. Ouraji - Department of Fisheries, Faculty of Animal Sciences and Fisheries, Sari Agricultural Sciences and Natural Resources University (SANRU), Sari, Iran

The development of the marine aquaculture industry has led to the generation of significant amounts of fish wastes. Marine farm wastes exert adverse effects on the surrounding area of the cages. On the other hand, wastes of fish and other aquatic animals are regarded as major sources of valuable natural bioactive compounds, including enzymes, proteins, bioactive peptides, oil, amino acids, collagen, gelatin, calcium, biopolymers, and water-soluble minerals. To investigate the potential of marine fish waste, the whole digestive system of yellowfin seabream (Acanthopagrus latus) was extracted for extraction and identification of trypsin enzyme. Fish (۱۷۹.۹۳±۹۳.۶۷ g; ۱۸۴±۲۸.۱۷ cm) were caught from the Persian Gulf and stored at -۲۰ °C. Yellowfin seabream were dissected and their whole digestive systems were removed. Samples were thoroughly washed with distilled water and purified through defatting using acetone and ammonium sulfate precipitation. The following issues were assessed: the total and specific activity of trypsin, protein determination, molecular weight, enzyme activity and stability in different pH values and temperatures. The obtained results indicated that specific activity and protein content of trypsin enzyme were ۴.۴ U and ۳.۴ mg/ml, respectively. The molecular weight of ۲۳ kDa was reported for trypsin using sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) method. Maximum activity and stability of trypsin were observed at ۶۰°C and ۴۵°C, respectively. Trypsin demonstrated maximum activity and stability at a pH value of ۸.۰. In general, the results of the current study suggested that trypsin extracted from the digestive system of yellowfin seabream has considerable potential for industrial applications, such as the food industry, owing to its characteristics and stability under alkaline conditions.

Enzyme purification, Yellowfin seabream (Acanthopagrus latus), Trypsin, Fish waste