Effect of Potassium on Saccharomyces cerevisiae Resistance to Fluconazole

Susceptibility of strain S288c of Saccharomyces cerevisiae to fluconazole was assayed in the presence and absence of KCl. Addition of 150 mM KCl renders the strain more sensitive to the antifungal agent. The effect is caused by the K(+) ion rather than the anion or the osmolarity of the medium. The increase in sensitivity does not modify the values of intracellular and extracellular pH established in the presence of KCl.