MEChanisMs of ChroMatE dEtoxifiCation in yEasts The main pathway of Cr(VI) (hexavalent chromium) detoxification in microorganisms involves its reduction to Cr(IIIChromium in trace amounts is beneficial to humans, animals, plants and microorganisms; it is an element essential for glucose and fat metabolism, stabilization of the tertiary structure of proteins and nucleic acids [3,15]. However, at high concentrations it is extremely toxic, mutagenic and carcinogenic, especially in its oxidized hexavalent form Cr(VI). The adverse health effects and diverse cellular and molecular reactions make the research on chromium toxicology and metabolism to be very crucial in terms of both environmental protection and clinical medicine. Parallel studies have been performed at molecular and cellular levels using yeasts, mammalian cells and transgenic mice. however the detailed mechanisms of the cell-chromium interactions are yet to be revealed.