Thymol-triggered lysis of Escherichia coli expressing Lactobacillus phage LL-H muramidase

Effective disruption of Escherichia coli cells is achieved by the intracell ularly accumulated recombinant murein hydrolase (Lactobacillus bacteriophag e LL-H muramidase) after the addition of 5 mM thymol, Thymol destroys the i ntegrity and electric potential of the cytoplasmic membrane, and as a conse quence the muramidase can access and hydrolyze the cell wall murein leading to cell lysis, Lysis occurred within 5 min after the addition of thymol an d seemed to be efficient at high culture densities, This lysis method does not require cell harvesting or addition of other cell wall weakening substa nces or exogenous enzymes, As a cell disruption method, thymol-triggered ly sis is as efficient as sonication in the presence of 1% Triton, Furthermore , thymol did not interfere with the purification steps of Mur by expanded b ed adsorption chromatography (EBA), suggesting that the lysis method presen ted here is well suited for large-scale production and purification of intr acellular proteins of E. coli.