Comparative toxicity of heavy metals to some yeasts isolated from Saudi Arabian soil

Soil yeasts including Candida tropicalis, Geotrichum capitatum, Rhodotorula minuta and Williopsis californica were isolated from Saudi Arabian soil. The effect of Cd, Cu, Pb, Mn, Ni and Co on the growth of these soil yeasts in Czapek-Dox liquid medium at different concentrations of these heavy metals was investigated. The results provide evidence of the accumulation of metals analysed in the cells of yeasts. These yeasts are able to survive and grow in a medium containing up to 400 μg/ml of metal ions tested.