Antimicrobial effect of simple lipids and its relation to surface film behaviour—I

Abstract

Iso-branched fatty acids possess fungistatic and bacteriostatic properties. It has been found that they are also able to strongly enhance the effect of conventional antimicrobial agents, which act inside the cell membrane. In a comparative study of various lipids a relation between this biological effect and the collapse properties of the corresponding monomolecular surface film on water has been observed. The mode of action has been investigated by measurements of the interaction with membrane lipids in a biological test system as well as in a membrane model system. It is shown that this type of membrane-active compounds increase the permeability of the lipid layer of the plasma membrane so that the protective barrier function is reduced and a molecular mechanism for this effect is proposed on the basis of the surface film results.