The Exclusion of D2O from the Hydration Sphere of FeSO4· 7H2O Oxidized by Thiobacillus ferrooxidans

Science  23 Dec 1983:
Vol. 222, Issue 4630, pp. 1331-1334
DOI: 10.1126/science.222.4630.1331


Infrared spectra demonstrate that neither FeSO4 · 7H2O nor its bacterial or abiotic hydrated oxidation products incorporate deuterium in acid D2O solutions. Deuterium exchange occurred as bridging OD when bacterially oxidized iron was precipitated from D2O 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.