THE DISTRIBUTION OF ELEMENTS IN CELLS OF THE METHYLOTROPHIC YEAST CANDIDA-BOIDINII AS DETERMINED BY ELECTRON-PROBE X-RAY-MICROANALYSIS OF ULTRATHIN FROZEN-DRIED CRYOSECTIONS

The contents of sodium, magnesium, phosphorus, sulphur, chlorine, potassium and zinc in intracellular compartments of methylotrophic yeast Candida boidinii grown in a xylose-limited chemostat were determined by the method of electron probe X-ray microanalysis of ultrathin frozen-dried cryosections. The highest concentrations of sodium, magnesium, phosphorus, potassium and zinc were found in the vacuole, while the distribution of chlorine in the cells was nearly homogenous. Sulphur was absent in the vacuole while nearly all zinc present within the cell was localised in the vacuole.