Antimicrobial activity of lysozyme is limited to Gram-positive bacteria. In mammalian and fish cells, lysozyme plays an
important defense role in the earlier stage of bacterial infection by enhancing the phagocytosis of bacteria. In an effort to expand the antibacterial activity of lysozyme to Gram-negative bacteria, lysozyme derivatives having bactericidal activity against Gram-positive as well as Gram-negative bacteria were prepared by covalent attachment of polysaccilarides
or fatty acids to lysozyme lysyl residues. The aatimicrobial effects of lysozyme conjugates against Gramn~
gative bacteria were associated with the degradation of the outer membrane in the bacteria and subsequent lysis of
the peptidoglycan in the cells. The safety of lysozyme conjugates prepared through controlled Maillard reaction has been
rt'ported