Study on chemical modification of lysozyme with ferulic acid and exhibiting an enhanced antimicrobial action

In order to extend the bactericidal spectrum of lysozyme against Gram-positive bacteria and Gram negative bacterial,lysozyme was modified by the covalent attachment of ferulic acid.Linkage of the organic acid to lysozyme was achieved by the constitution of amide binding between the carboxyl group of ligand and primary amino group of the lysozyme mediated by EDAC.The results showed that,compared to natural lysozyme,the lytic activity of modified lysozyme was reduced.In contrast,it enhanced bactericidal spectrum,Gram-negative bacterial growth could be strongly inhibited.The minimal inhibitory concentration against E.coli and Salmonella was 0.5mg /mL for the modified lysozyme.But the efficacy of modified lysozyme against Staphylococcus aueres was slightly reduced.