Purification and characterization of a lysozyme from a marine microorganism / 生物工程学报

ABSTRACT

A novel lysozyme was purified from a marine microorganism and its major characteristics were studied. Cell-free supernatant was prepared by centrifugation of culture broth, ultrafiltration using a hollow fiber (molecular weight cut off, 50kD) and concentration using a hollow fiber (molecular weight cut off, 10kD). The crude lysozyme was purified 34.7 fold to electrophoretic homogeneity with a recovery of 24.1% by CM-Sepharose FF cationic-exchange and Sephadex G-100 gel chromatography. The relative molecular weight of this lysozyme was determined as about 39 kD. The optimum pH and temperature towards Micrococcus lysodleikticus were pH 8.0 and 35 degrees C respectively, and the enzyme was stable at temperature below 50 degrees C and pH 5.0 - 10.0. The lysozyme activity was slightly enhanced by Zn2+ and Cu2+ and slightly inhibited by Mn2+ and Ag+. The lysozyme showed good compatibility to many common chemical agents such as EDTA (0.1%) and KH2 PO4 (1.0%). The lysozyme had broad-spectrum against many bacteria, including a number of pathogens, which were resistant to egg-white lysozyme.