Antibacterial activity of hen egg white lysozyme modified by thermochemical technique

Lysozyme is an important component of egg white with antibacterial properties especially against Gram-positive bacteria. Research indicates that the range of lysozyme activity may be extended thanks to chemical or physical modifications. The purpose of the study was to determine the effectiveness of antibacterial action against selected strains of bacteria of lysozyme modified by the thermochemical technique. Our investigations indicated a possibility of extending the range of lysozyme activity using modification. We found that under the adopted conditions modification promotes an increased polymerisation of lysozyme. It was observed that the temperature and time of modification have an effect on the content of the forming polymers. It was found that the application of lysozyme modification leads to an increase in its antibacterial activity in comparison to the activity of lysozyme monomer. The experiments have shown that the used lysozyme preparations demonstrate different activity in relation to different types of bacteria. The observed increase in antibacterial activity of modified lysozyme preparations against Gram-negative bacteria were not associated with a decrease of that activity against Gram-positive bacteria. The greatest reduction of growth of the examined Gram-negative bacteria species was recorded for the preparation which contained the highest quantity of dimer (34–37.6%). A more effective action against bacteria Staphylococcus epidermidis was observed for preparations containing 25–27% of dimer.