NEW ANTIMICROBIAL CHARACTERISTICS OF LYSOZYME DEXTRAN CONJUGATE

Lysozyme-dextran conjugate prepared by Maillard reaction revealed significant antimicrobial activity for both Gram-negative and Gram-positive bacteria. Estimating from the binding weight ratio, about two molar dextrans were linked covalently with one molar lysozyme. Lytic activity of the conjugate was considerably reduced when measured by using Micrococcus lysodeikticus as a substrate, while it remained about 80% that of native lysozyme when measured by using glycol chitin. The heat stability of lysozyme activity was increased by linking with dextran. The emulsifying properties of the conjugate were much higher than those of native lysozyme. These results suggest that an antimicrobial activity of the lysozyme-dextran conjugate for Gram-negative bacteria comes from the remaining stable lysozyme activity and the excellent emulsifying properties by which the outer membrane is solubilized.