Fingerprints of partial oxidation of biogenic magnetite from cultivated and natural marine magnetotactic bacteria using synchrotron radiation.
Daniel Rodelli,Luigi Jovane,Andrew P. Roberts,Jefferson Cypriano,Fernanda Abreu,Ulysses Lins +5 more
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TLDR
XANES spectra for Fe in magnetotactic bacteria samples from recent sediments indicate that oxidation of magnetite to maghemite increases with depth in the sediment due to longer exposure to molecular oxygen, relevant to understanding magnetic signatures carried by magnetofossils in oxic sediments and sedimentary rocks of different ages.Abstract:
Magnetotactic bacteria are a multi-phyletic group of bacteria that synthesize membrane-bound magnetic minerals. Understanding the preservation of these minerals in various environments (e.g., with varying oxygen concentrations and iron supply) is important for understanding their role as carriers of primary magnetizations in sediments and sedimentary rocks. Here we present X-ray near edge structure (XANES) spectra for Fe in magnetotactic bacteria samples from recent sediments to assess surface oxidation and crystal structure changes in bacterial magnetite during early burial. Our results are compared with a XANES spectrum of cultivated Magnetofaba australis samples, and with magnetic properties, and indicate that oxidation of magnetite to maghemite increases with depth in the sediment due to longer exposure to molecular oxygen. These results are relevant to understanding magnetic signatures carried by magnetofossils in oxic sediments and sedimentary rocks of different ages.read more
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Microbe-Mediated Extracellular and Intracellular Mineralization: Environmental, Industrial, and Biotechnological Applications
TL;DR: The different types of microbe‐mediated biomineralization that occur in nature, their mechanisms, as well as their applications are elucidated to create a backdrop for future research.
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Diagenetic Fate of Biogenic Soft and Hard Magnetite in Chemically Stratified Sedimentary Environments of Mamanguá Ría, Brazil
Daniel Rodelli,Luigi Jovane,Martino Giorgioni,Martino Giorgioni,E. S. Rego,Flaminia Cornaggia,Mariana Benites,P. Cedraz,Glaúcia Bueno Benedetti Berbel,Elisabete de Santis Braga,Andréa Teixeira Ustra,Fernanda Abreu,Andrew P. Roberts +12 more
TL;DR: The authors acknowledge funding from FAPESP grants 2012/212123 and 2011/22018•3, respectively, and L. P. R. and A. A. J.
Journal ArticleDOI
Diverse phylogeny and morphology of magnetite biomineralized by magnetotactic cocci.
Peiyu Liu,Yan Liu,Xiang Zhao,Andrew P. Roberts,Heng Zhang,Yue Zheng,Fuxian Wang,Lushan Wang,Nicolas Menguy,Nicolas Menguy,Yongxin Pan,Jinhua Li +11 more
TL;DR: The results indicate that magnetofossil morphology could be a promising proxy for retrieving paleobiological information about ancient MTB and confirms that magnetosome biomineralization is controlled strictly by the MTB cell and differs among species or strains.
Journal ArticleDOI
Magnetite magnetofossils record biogeochemical remanent magnetization in hydrogenetic ferromanganese crusts
TL;DR: In this article, the authors show that nanometer-scale magnetite crystals found in Fe-Mn crusts from the Pacific Ocean and South China Sea are magnetosome fossils based on their narrow size range, chain arrangement, chemical purity, and crystallographic perfection, as indicated by transmission electron microscopy.
Journal ArticleDOI
Paleoenvironmental signature of the Selandian-Thanetian Transition Event (STTE) and Early Late Paleocene Event (ELPE) in the Contessa Road section (western Neo-Tethys)
Rodolfo Coccioni,Fabrizio Frontalini,Rita Catanzariti,Luigi Jovane,Daniel Rodelli,Ianco M. M. Rodrigues,Jairo F. Savian,Martino Giorgioni,Bruno Galbrun +8 more
TL;DR: The Selandian-Thanetian Transition Event (STTE) has been recognized and well constrained in the western Tethys Contessa Road section (Gubbio, Italy) through high-resolution biostratigraphic, geochemical, and rock-magnetic data as mentioned in this paper.
References
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Oxidation state and coordination of Fe in minerals: An Fe K-XANES spectroscopic study
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Rock magnetic criteria for the detection of biogenic magnetite
TL;DR: In this paper, a combination of room temperature coercivity analysis and low temperature remanence measurements provided a characteristic magnetic signature for intact chains of single domain (SD) particles of magnetite from magnetotactic and dissimilatory iron-reducing bacteria.