Strains of Acidiphilium sp. resistant to four heavy metals such as 10 mM Co2+, 100 mM Ni2+, 10 mM Cd2+ and 0.01 mM Hg2+ were obtained. An addition of ferrous or ferric ions in the culture medium of Acidiphilium sp. increased Co+2 resistance of the cells. The mechanism of Co2+ resistance was studied. Cobaltous ion (50 mM) inhibited uptake of 14C-glucose into intact cells and the activity of glucose oxidation. The activity of glucose oxidation was restored by adding ferrous or ferric ions (4 mM) in the reaction mixture, but 14C-glucose uptake activity was not restored. Ferrous or ferric ions inhibited an accumulation of Co2+ in the strain, suggesting that inhibition of Co2+ uptake by ferrous and ferric ions is responsible for the improvement of Co+2 resistance by those ions.
ASJC Scopus subject areas