Study Of Purification Technology Of Lysozyme From Egg White

Lysozyme is a kind of glucoside hydrolytic enzyme,and its molecular weight is about 14000-15000Da.Lysozyme can hydrolyze the glucoside bond 8-1,4 between N-acetylglucosamine and N-acetyl muramic acid , so that it can dissolve the cell wall of gram-positive bacteria and bacteriolyze. It can be applied in many areas, for example, in food and drink fields as antiseptic substance and in medical domain as germicide.This research compared the purified effects of different treatment ,such as heat treatment,ion resin exchange method and ultrafiltration. Heat treatment utilized the different denaturation temperature and isoelectric points between Lysozyme and egg albumin. Ion resin exchange method was based on the special absorption between ion resin and lysozyme basic group.While According to different molecular weight between Lysozyme and egg albumin, 30000 Da hyperfiltration membrane is used during ultrafiltration.The results showed that, the purified effect and yields of heat treatment were ineffective, what's more, changing pH and heat treatment would decrease the activity of Lysozyme greatly, And the treated egg albumin by this means could not be recycled any more, thus this reduced the productive value largely. By ion resin exchange method, 0.28mol/L sodium chloride can elute Lysozyme sufficiently from resin. The optimal absorption condition: room temperature; 1: 6.18 volume ratio of resin and egg white; pH6 egg white; 2 times dilution; 80 minutes absorption time. Under such conditions, It could achieve the best activity and yield of Lysozyme, the activity and yield could reach 20000U/mg and 86.6%,and the purify of Lysozyme is 100%. While applied with 30000Da hyperfiltration membrane, Lysozyme could gain 100% purity, 18500U/mg activity and 73.1% yield.