INTERACTIONS OF RARE-EARTH ELEMENT IONS WITH THE CELLS OF CANDIDA-UTILIS

By using X-ray microanalysis, the mechanism of sorption of rare earth elements (REE) and their localization in cells of Candida utilis were found to depend on the metal ion speciation in the solution, the perme ability of the cytoplasmic membrane (CPM), and the elemental compositi on of cells. Sorption capacity of the yeast cells increased with the i ncrease in the pH of the solution in accordance with the hydrolyzation degree of the metal ions. Cells with undisturbed CPM permeability did not sorb either scandium at pH values below 4.5 or lanthanum or samar ium at pH values below 5.0. Such cells sorbed rare earth elements with the help of their surface structures. Sorption of REE from the acid s olutions was only realized by the cells with impaired CPM. In this cas e, REE were accumulated inside the cells due to interaction with phosp horus-containing compounds; the amount of sorbed REE depended on the c ontent of phosphorus in the yeast cells.