EN
Cadmium is an environmental pollulant highly toxic to all forms of life. In this paper we studied by polarography the effect of the environment on cadmium speciation and also the effect of this speciation on 109Cd uptake and toxicity to living cells of cadmium-sensitive Staphylococcus aureus 17810S in different media. It was found that the magnitude of passive ,09Cd adsorption was proportional to the content of free Cd2+ in the medium (cadmium speciation). In contrast, the magnitude of energy-requiring l09Cd accumulation did not depend on cadmium speciation and was similar in all media. This could be due to the higher affinity of Cd2+ to the Mn2+ transport system than to the complexing ligands in the medium. Thus, cadmium uptake by S. aureus 17810S depends both on environmental and cellular factors and under all circumstances results in strong toxicity to living cells.