Effect of heavy-metals on amylolytic activity of the soil yeasts Geotrichum capitatum and Geotrichum candidum

This study investigated the ability of the soil yeasts Geotrichum candidum and Geotrichum capitatum to produce extracellular amylase in Czapek-Dox liquid medium amended with different concentrations of Cd, Co, Cu, Mn, Ni and Pb. Yeasts were able to survive and grow in the medium containing up to 400 μg/ml of metal ions. Addition of heavy metals caused a highly significant inhibition of amylase production by soil yeasts tested. The amylolytic activity of G. candidum and G. capitatum decreased as the concentration of heavy metals increased. The soil yeast G. candidum exhibited the highest amylolytic activity.