COPPER RESISTANT STRAIN <i>Candida tropicalis</i> ROMCU5 INTERACTION WITH SOLUBLE AND INSOLUBLE COPPER COMPOUNDS
The focus of the study was interaction of Candida tropicalis RomCu5 isolated from highland Ecuador ecosystem with soluble and insoluble copper compounds. Strain C. tropicalis RomCu5 was cultured in a liquid medium of Hiss in the presence of soluble (copper citrate and CuCl 2) and insoluble (CuO and CuCO 3) copper compounds. The biomass growth was determined by change in optical density of culture liquid, composition of the gas phase was measured on gas chromatograph, redox potential and pH of the culture fluid was defined potentiometrically. The concentration of soluble copper compounds was determined colorimetrically. Maximal permissible concentration of Cu 2+ for C. tropicalis RomCu5 was 30 000 ppm of Cu 2+ in form of copper citrate and 500 ppm of Cu 2+ in form of CuCl 2. C. tropicalis was metabolically active at super high concentrations of Cu 2+, despite the inhibitory effect of Cu 2+. C. tropicalis immobilized Cu 2+ in the form of copper citrate and CuCl 2 by its accumulation in the biomass. Due to medium acidification C. tropicalis dissolved CuO and CuCO 3. High resistance of C. tropicalis to Cu 2+ and ability to interact with soluble and insoluble copper compounds makes it biotechnologically perspective.