Georges Ona-Nguema

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Sphaerotilus natans is a neutrophilic iron-related sheath-forming filamentous microorganism that presents dual morphotype: single cells and ensheathed cells forming filaments. As S. natans has been proposed as a sorbent for inorganic pollutants and it is occasionally involved in bulking episodes, elucidating factors affecting its filamentous growth is of(More)
Magnetotactic bacteria perform biomineralization of intracellular magnetite (Fe3O4) nanoparticles. Although they may be among the earliest microorganisms capable of biomineralization on Earth, identifying their activity in ancient sedimentary rocks remains challenging because of the lack of a reliable biosignature. We determined Fe isotope fractionations by(More)
Lepidocrocite, a widespread environmentally relevant iron oxyhydroxide, has been investigated for decades using 57 Fe Mössbauer spectroscopy and magnetic measurements. However, a coherent and comprehensive interpretation of all the data is still lacking due to seemingly contradictory interpretations. On one hand, temperature dependence of magnetic(More)
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