Characterization of Partially Purified and Immobilized Protease Extracted from Silver Catfish (Pangasius Sutchi) Viscera

Abstract

Viscera is known as one of the richest sources of proteolytic enzymes. However, the biggest problem regarding enzyme is the rapid deterioration and lose in functional properties due to inefficient treatment and improper storage condition. Therefore, in this study, protease from silver catfish viscera have been extracted, partially purified by acetone precipitation method and immobilized in the calcium alginate beads. Concentrations of 2.99% (w/v) sodium alginate and 0.30 M calcium chloride were used to produce the immobilized protease. Then, the partially purified and immobilized protease were characterized in different range of pH, temperature and storage period in order to establish a greater protease stability during storage and increase in its efficiency. Proteolytic activity of the partially purified and immobilized protease in the alginate beads were measured by using casein as a substrate. The highest proteolytic activity for partially purified protease was recorded at pH 4 (5709.76 CDU/mg) and 40 °C (6061.14 CDU/mg) and for immobilized protease at pH 5 (3987.85 CDU/mg) and 50 °C (4956.54 CDU/mg). For storage stability, the partially purified protease has optimum storage temperature at – 40 °C while the immobilized protease at 4 °C. At optimum storageondition, the partially purified protease and immobilized protease have storage efficiency of 17.44 and 24.50%, respectively until 6th days of storage. Overall, the results showed that immobilization of protease improved enzyme limitation such as proteolytic activity, stability and the purity.