The Exclusion of D2O from the Hydration Sphere of FeSO4{middle dot} 7H2O Oxidized by Thiobacillus ferrooxidans.

Infrared spectra demonstrate that neither FeSO(4) . 7H(2)O nor its bacterial or abiotic hydrated oxidation products incorporate deuterium in acid D(2)O solutions. Deuterium exchange occurred as bridging OD when bacterially oxidized iron was precipitated from D(2)O solutions as ferric hydroxysulfates. The exclusion of deuterium depended upon the stabilization of aquated Fe(II) and Fe(III) complexes by sulfate ions in outer-sphere coordination and is consistent with the requirement and postulated role of sulfate in iron oxidation by Thiobacillus ferrooxidans.