Mercury-induced Loss of K+ from Yeast Cells Investigated by Electron Probe X-ray Microanalysis

Abstract

The Hg-induced loss of K+ from yeast [Saccharomyces cerevisiae] cells is an all-or-none effect. This hypothesis was tested by analyzing individual yeast cells by energy-dispersive X-ray microanalysis. A dual effect of Hg was observed. The cell population was split into 2 parts: 1 part consisted of cells that suffered a (nearly) complete loss of K+-the number of these cells increased with increasing concentrations of HgCl2; the other consisted of cells that had only lsot part of their K+ content- these cells showed a normal distribution around a central value that decreased with increasing concentrations of HgCl2. The effect of Hg is more complex than originally suggested and, in addition to an all-or-none effect, a gradual loss of K+ occurs.