USE OF INAA TO STUDY SE, SB, ZN AND CO LEVELS OF YEAST-CELLS

Yeast cells, Saccharomyces cerevisiae, were exposed to Sb(V) (10(-5) M ) and SeO2 (10(-4) M) or seleno-cystine (CySe)(2) (5 x 10(-5) M). Se, Sb, Zn and Co levels of the yeast were measured by instrumental neutro n activation analysis. The results obtained show that in the absence o f Se, Sb is taken up by the cells and the highest concentration of Sb in the yeast was observed during the initial 2.5 h of incubation. Both Se-compounds resulted, in general, in a minute decrease of uptake yie ld of Sb by the cells. This effect can be particularly observed in the presence of SeO2. The presence of Sb in the yeast medium slightly inc reased the Se level only after long incubation times. Se uptake by the yeast was higher (regardless of Sb dosage) when the yeast was incubat ed in the medium containing (CySe), (in comparison with SeO2). The pre sence of Se-compounds and/or Sb caused decrease in the levels of Zn fo und in the cells. While SeO2 presence resulted in minor changes of the Co level of the yeast, the combined presence of Sb and Se-compounds p roduced the significant enhancement of Co abundance. The similar effec t was noted in the yeast incubated in a medium containing only (CySe)( 2) or Sb.