Studies on preparation and characteristic of the marine low temperature lysozyme

The study on the physical and chemical properties and purification of low temperature lysozyme of a marine bacterium is conducted.The strain is cultured at 20℃ for 40h on a shaker in the medium consisting of glucose, yeast extract, tryptone and artificial seawater. The supernatant of the lysozyme with activity about 150U/ml is acquired. The supernatant is purified by the procedures of lyperfiltration technology, dialyzing method, CM Sepharose FF positive ion column chromatography and perfusion chromatography. The enzyme electrophoreticly purified is obtained. The result shows that the enzyme consists of 143 amino acids, its molecular weight being 16KD, isoeleotric point 9 28, Km value 72μg/ml.The optimum pH of the lysozyme reacting to Micrococcus lysodleikticus is 4 5 to 8 0, the optimum temperature ranges from 5℃to 50℃. The lysozyme remains the activity of 55% at 5℃.It has certain anti oxidation stability. The lysozyme is a typical low temperature enzyme and can keep high activity at low temperature. The lysozyme has broad spectrum antibiotic reaction, which may kill gram positive or gram negetive germs.