Adsorption of pneumocins and aerocins on bacterial cells.

Adsorption of aerocins 1a-E26, 1b-E47, 1b-E43, 2-E26, 2-E47 and pneumocins A-114 and A-902 was found to be dependent on the presence of specific receptors on the surface of sensitive bacteria. Resistant mutants, selected by these bacteriocins, were incapable of adsorption owing to loss or altered structure of receptors. Maximal numbers of Killing Units of pneumocins and aerocins adsorbed by one bacterial cell of sensitive strains were determined. Kinetics of adsorption and degree of killing of bacteria in relation to concentration of bacteriocins were studied. The lethal effect on bacteria was of the "single hit" type, i. e. one particle of aerocin respectively pneumocin killed one bacterial cell.