Purification and characterization of lysozyme from the intestine of sea cucumber

A kind of lysozyme from the intestine of sea cucumber was purified by Cloud Point Extraction(CPE),cation-exchange chromatography with CM52 cellulose and gel filtration chromatography with Sephadex G-75.The specific activity,purification fold and yield of lysozyme were 3 026.1 U/mg,18.7 and 46%,respectively.The final enzyme preparation was nearly homogeneous in SDS-PAGE and its molecular weight was estimated as approximately 16 000.The optimal pH and temperature against Micrococcus lysodleikticus were pH 6.5 and 35 ℃,respectively,and the enzyme was stable at temperature below 45 ℃ and pH 4.0-8.0.The purified lysozyme showed broad-spectrum against many bacteria,not only inhibiting the growth of Gram-positive bacteria,but also Gram-negative bacteria as well as a number of pathogens.