Dielectric properties of yeast cells: Effect of some ionic detergents on the plasma membranes

Abstract

Dielectric measurements were made on suspensions of yeast cells treated with two homologous series of sodium alkyl (C8, C10, C12, C14) sulfonates and alkyl (C8, C10, C12, C14, C16, C18) benzyl dimethyl ammonium chlorides over a frequency range of 10 kHz to 100 MHz. Dielectric dispersions observed for the suspensions of intact yeast cells are found to be reduced by treatment with these detergents, the reduction being accompanied by a decrease in packed volume of the cells and by a leakage of intracellular compounds. The reduction of dielectric dispersions is considered to be caused by a decrease in volume of the cells in suspensions and an increase in conductivity of the cell membranes. An effect of the alkyl chain length of the detergents on the reduction of dielectric dispersions is also examined for these ionic detergents. The reducing effect shows the maximum at the alkyl chain, C14 for sodium alkyl sulfonates and at C16 for alkyl benzyl dimethyl ammonium chlorides. These results are consistent with hemolysis and bactericidal activity.