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Anaerobic, Nitrate-Dependent Oxidation of Pyrite Nanoparticles by Thiobacillus denitrificans
journal contribution
posted on 2012-02-21, 00:00 authored by Julian Bosch, Keun-Young Lee, Guntram Jordan, Kyoung-Woong Kim, Rainer U. MeckenstockPyrite is a key mineral in the global biogeochemical
cycles of
sulfur and iron, yet its anaerobic microbial oxidation has eluded
geochemists and microbiologists for decades. Recent reports indicated
that anaerobic oxidation of pyrite is occurring, but the mechanism
remains unclear. Here, we provide evidence for the capability of Thiobacillus denitrificans to anaerobically oxidize a putatively
nanosized pyrite particle fraction with nitrate as electron acceptor.
Nanosized pyrite was readily oxidized to ferric iron and sulfate with
a rate of 10.1 μM h–1. The mass balance of
pyrite oxidation and nitrate reduction revealed a closed recovery
of the electrons. This substantiates a further “missing lithotrophy”
in the global cycles of sulfur and iron and emphasizes the high reactivity
of nanominerals in the environment.