Study Of Extracting Lysozyme From Hen Egg White

This thesis have studied of the process of extracting lysozyme from egg white by salting-out and ion-exchange, optimized the technical parameter. The impurity in lysozyme precipitation was eliminated by heat denaturalization. Then lysozyme crystal was obtained by 0.24% yield in weight and 61% yield in enzyme activity. This method is simple in operation, higher in yield, suit for production in small scale. In process of ion- exchange, the mixed resin of H+ type and Na+ type can adjust pH of egg white. This method didn't induct the inorganic impurity, and reduced the impurity from the process, didn't impact the quality of residual egg white, in favor of the reuse of egg white. This method can produce lysozyme by 0.40% yield in weight and 90% yield in enzyme activity. The acetone can precipitate lysozyme without rotting equipment, polluting environment, prolonging the process cycle. This method can produce lysozyme by 0.41% yield in weight and 87% yield in enzyme activity, reduce the cost, and increase the reuse of material. The ethanol can replace the acetone to precipitate lysozyme, and NaCl can be used to elute lysozyme from resin. This method can produce lysozyme by 0.41% yield in weight and 82% yield in enzyme activity. A simple colorimetric method for the determination of lysozyme activity was studied. The experimental data showed that the colorimetric method is better than the turbidimetric method in the fidelity of the result. The colorimetric method is suit for determination of lysozyme activity in process of lysozyme production.