Biochemical characterisation of lysozyme extracted from rainbow trout Oncorhynchus mykiss (Walbaum, 1792)

Abstract

In the present study, lysozyme was extracted from spleen tissue of rainbow trout Oncorhynchus mykiss (Walbaum, 1792) and partially purified by ammonium sulfate precipitation. Optimum pH and temperature as well as effects of different salt concentrations of NaCl, MgCl 2 , KCl and urea on enzyme activity were evaluated. The enzyme activity was assayed using a suspension of Micrococcus lysodeikticus as substrate. Results showed that lysozyme extracted from the spleen of O. mykiss has its optimum activity at high temperature (60ºC) and low pH (5.8) conditions and the enzyme activity was found to vary with different salt concentrations which were found related to the environmental conditions of natural habitats of O. mykiss.