Studies on the mode of action of nisin

Abstract

The interference of the polypeptide antibiotic nisin with membrane function and murein synthesis was studied. The inhibition of the in vivo synthesis of murein in Bacillus subtilis and the resistance of Mycoplasma mycoides to nisin, suggest that the membrane may be excluded as a target. On the other hand a general inhibition of macromolecule syntheses in Micrococcus luteus supports the assumption that the cytoplasmic membrane is a target. In addition, an antagonistic effect on growth inhibition by nisin with both, cytoplasmic membranes and isolated phospholipid components of membranes was demonstrated. The lysis of phospholipid liposomes by nisin and the sensitivity at increased concentration of antibiotic of organisms lacking murein in their cell walls provide further evidence for the cytoplasmic membrane as a target. We therefore assume that the antimicrobial effect of nisin is caused by its interaction with phospholipid components of the cytoplasmic membrane followed by an interference with the membrane function. The sensitivity against nisin is increased in organisms with murein in their cell walls because the inhibition of this polymer causes an additional, inhibitory effect synergistic to the disturbance of the membrane function. © 1986.