Activities of Iron Oxidase and Hydrogen Sulfide: ferric Ion Oxidoreductase of Thiobacillus ferrooxidans isolated from natural environments

It has been reported that both iron oxidase and hydrogen sulfide: ferric ion oxidoreductase (SFORase) were involved in bacterial leaching of metal ions from sulfide ores, and the amount of Cu2+ solubilized from copper ore by iron-oxidizing bacterium differed from strain. The activities of iron oxidase SFORase of iron-oxidizing bacteria isolated from the natural environments were determined. Iron-oxidizing activity and SFORase activity of 200 strains ranged from 1.20-1.65γmol/mg/min and from 0.11-2.80 γmol/mg/min, respectively. The findings that a remarkable difference was observed in the levels of SFORase activity, but not in iron-oxidizing activity, suggest that SFORase, but not iron oxidase, is the enzyme that determines the bacterial leaching activity of this bacterium.