Lysis of Escherichia coli cells by lysozyme: Discrimination between adsorption and enzyme action

[Display omitted] • The dual effect on ionic strength on lysis of gram-negative bacteria has been found. • The boarder conditions for enzymatic Escherichia coli lysis have been explained. • The limiting factors of the lysis have been studied and proved. The key factors of enzymatic lysis of cells are the interaction between the enzyme and the cell – catalytic and non-catalytic adsorption of enzyme on cell surface. Here, the studies of lysis of intact Escherichia coli cells by chicken egg white lysozyme were performed. It was found that the ionic strength has a dual effect onto the system. On the one hand, the desorption constant of the enzyme increases with the increase of the solution ionic strength, which results in a better enzyme performance. On the other hand, due to the higher osmosis, the cell lysis rate decreases with the increasing of ionic strength of the system. It was found that pH 8.6 and 30 mM NaCl are optimal conditions for lysis of E. coli cells by lysozyme.