Antimicrobial action of dodecyldiethanolamine: induced membrane damage in Escherichia coli

Studies on the uptake of the antimicrobial agent N-dodecyldiethanolamine by Escherichia coli show that it rapidly penetrates the cell wall and damages the cytoplasmic membrane. Membrane damage is evident from the induced release of potassium ions and other cytoplasmic components from whole cells and from the lytic effect upon isolated spheroplasts. Concentrations of 0.4 mM and below lyse spheroplasts whereas higher concentrations cause coagulation of the cytoplasm which prevents lysis. The effect of membrane damage upon glucose oxidation in whole cells is also dependent upon the concentration of dodecyldiethanolamine. Concentrations of 0.4 mM and below stimulate oxygen uptake and higher concentrations inhibit it.