Factors affecting the adsorption of buchnericin LB, a bacteriocin produced by Lactocobacillus buchneri

Abstract

Buchnericin-LB adsorbs to gram-positive but not to gram-negative bacteria. The tested gram-positive bacteria were species of Lactobacillus, Pediococcus, Leuconostoc, Enterococcus, Lactococcus, Listeria, Bacillus, Staphylococcus; gram-negative bacteria belonged to the genera Salmonella, Escherichia, Yersinia and Pseudomonas. Buchnericin-LB adsorption depended on pH but not on time and temperature. Also some anions of salts and lipoteichoic acid reduced or inhibited its adsorption. Treatment of cells and cell walls of sensitive bacteria with detergents, organic solvents or enzymes did not affect subsequent binding of buchnericin-LB. Treatment with buchnericin-LB caused sensitive cells to lose high amounts of intracellular K+ ions and UV-absorbing materials and became more permeable to o-nitrophenol-β-D-galactopyranoside. Buchnericin-LB (640-2560 AU/ml) decreased the colony forming units (99%) and absorbance values of Listeria monocytogenes and Bacillus cereus. These results indicate that the mode of action of buchnericin-LB is bactericidal and its lethal effect is very rapid.