Factors affecting the adsorption of bacteriocins to Lactobacillus sakei and Enterococcus sp.

Bacteriocins bacJW3BZ and bacJW6BZ produced by Lactobacillus plantarum, and bacJW11BZ and bacJW15BZ produced by Lactobacillus fermentum, inhibit Gram-positive and Gram-negative bacteria. Treatment of Enterococcus sp. HKLHS and Lactobacillus sakei DSM 20017 with these bacteriocins deformed the cells and resulted in DNA and beta-galactosidase leakage. The bacteriocins adsorbed to sensitive and resistant strains. Optimal adsorption of bacJW3BZ and bacJW6BZ to Enterococcus sp. HKLHS was recorded at pH 10.0, whereas adsorption of bacJW11BZ and bacJW15BZ was favored at pH 4.0-8.0 and 2.0-4.0, respectively. Adsorption to L. sakei DSM 20017 was less influenced by pH. Incubation temperature had a major influence on the adsorption of bacJW6BZ and bacJW11BZ to sensitive cells, with better results recorded below 30 degrees C. Although variable results were recorded for bacJW3BZ and bacJW15BZ, optimal adsorption occurred between 37 and 60 degrees C. Variable levels of adsorption were recorded in the presence of inorganic salts and solvents, and this seems to be species-specific. Maximal adsorption (100%) was recorded for bacJW3BZ and bacJW15BZ to L. sakei DSM 20017 in the presence of most inorganic salts and solvents tested. Maximal adsorption of bacJW6BZ to Enterococcus sp. HKLHS (50%) was recorded in the presence of Triton X-114 and little (17%) or no adsorption in the presence of other reagents.