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Accumulation of Amorphous Cr(III)–Te(IV) Nanoparticles on the Surface of Shewanella oneidensis MR‑1 through Reduction of Cr(VI)
journal contribution
posted on 2014-12-16, 00:00 authored by Dong-Hun Kim, Sunhwa Park, Min-Gyu Kim, Hor-Gil HurIndustrial effluents
constitute a major source of metal pollution
of aquatic bodies. Moreover, due to their environmental persistence,
toxic metal pollution is of special concern. Microbial reduction is
considered a promising strategy for toxic metal removal among the
several methods available for metal remediation. Here, we describe
the coremediation of toxic Cr(VI) and Te(IV) by the dissimilatory
metal reducing bacterium-Shewanella oneidensis MR-1.
In the presence of both Cr(VI) and Te(IV), S. oneidensis MR-1 reduced Cr(VI) to the less toxic Cr(III) form, but not Te(IV)
to Te(0). The reduced Cr(III) ions complexed rapidly with Te(IV) ions
and were precipitated from the cell cultures. Electron microscopic
analyses revealed that the Cr–Te complexed nanoparticles localized
on the bacterial outer membranes. K-edge X-ray absorption spectrometric
analyses demonstrated that Cr(III) produced by S. oneidensis MR-1was rapidly complexed with Te(IV) ions, followed by formation
of amorphous Cr(III)–Te(IV) nanoparticles on the cell surface.
Our results could be applied for the simultaneous sequestration and
detoxification of both Cr(VI) and Te(IV) as well as for the preparation
of nanomaterials through environmental friendly processes.