Micro‐ and nano‐scale mineralogical characterization of Fe(II)‐oxidizing bacterial stalks
Autor: | Ruggero Vigliaturo, Alessandra Marengo, Ileana Pérez-Rodríguez, Goran Dražić, Erica Bittarello, Reto Gieré |
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Rok vydání: | 2020 |
Předmět: |
EELS
Goethite 010504 meteorology & atmospheric sciences Iron engineering.material 010502 geochemistry & geophysics Ferric Compounds 01 natural sciences Article Ferrihydrite stalk mineral speciation Fe redox state organo-mineral stalk STEM Ferrous Compounds Minerals Nanostructures Oxidation-Reduction Sweden Bacteria Oxidizing agent Scanning transmission electron microscopy Lepidocrocite Spectroscopy Dissolution Ecology Evolution Behavior and Systematics 0105 earth and related environmental sciences General Environmental Science Mineral Chemistry Chemical engineering visual_art visual_art.visual_art_medium engineering General Earth and Planetary Sciences |
Zdroj: | Geobiology |
ISSN: | 1472-4669 1472-4677 |
Popis: | Neutrophilic, microaerobic Fe(II)-oxidizing bacteria (FeOB) from marine and freshwater environments are known to generate twisted ribbon-like organo-mineral stalks. These structures, which are extracellularly precipitated, are susceptible to chemical influences in the environment once synthesized. In this paper, we characterize the minerals associated with freshwater FeOB stalks in order to evaluate key organo-mineral mechanisms involved in biomineral formation. Micro-Raman spectroscopy and Field Emission Scanning Electron Microscopy revealed that FeOB isolated from drinking water wells in Sweden produced stalks with ferrihydrite, lepidocrocite and goethite as main mineral components. Based on our observations made by micro- Raman Spectroscopy, field emission scanning electron microscopy and scanning transmission electron microscopy combined with electron energy-loss spectroscopy, we propose a model that describes the crystal-growth mechanism, the Fe-oxidation state, and the mineralogical state of the stalks, as well as the biogenic contribution to these features. Our study suggests that the main crystal-growth mechanism in stalks includes nanoparticle aggregation and dissolution/re-precipitation reactions, which are dominant near the organic exopolymeric material produced by the microorganism and in the peripheral region of the stalk, respectively. |
Databáze: | OpenAIRE |
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