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Updated: May 24, 2026
09:45
Laboratory Simulation of an Iron(II)-rich Precambrian Marine Upwelling System to Explore the Growth of Photosynthetic Bacteria
Published on: July 24, 2016
Bacteriogenic Fe(III) (oxyhydr)oxides characterized by synchrotron microprobe coupled with spatially resolved
Satoshi Mitsunobu1, Fumito Shiraishi, Hiroko Makita
1Institute for Environmental Sciences, University of Shizuoka, 52-1 Yada, Suruga-ku, Shizuoka 422-8526, Japan. mitunobu@u-shizuoka-ken.ac.jp
Environmental Science & Technology
|February 25, 2012
Summary
Microbes drive geochemical cycles through biomineralization, but mechanisms remain unclear. A new technique combining fluorescence in situ hybridization (FISH) and micro X-ray absorption fine structure spectroscopy (μ-XAFS) reveals microbe-specific mineral formation in situ.
Area of Science:
- Environmental microbiology
- Geochemistry
- Analytical chemistry
Background:
- Microbes are crucial for geochemical cycling via biomineralization.
- Environmental biomineralization mechanisms lack detailed in situ analytical techniques.
- Iron-oxidizing bacteria (IOB) play a key role in iron cycling.
Purpose of the Study:
- To develop and apply a novel technique for high-resolution characterization of microbe-associated biominerals.
- To investigate the in situ biomineralization processes mediated by iron(II)-oxidizing bacteria (IOB).
Main Methods:
- Combined in situ phylogenetic analysis using fluorescence in situ hybridization (FISH).
- Utilized synchrotron microprobe analysis, specifically micro X-ray absorption fine structure spectroscopy (μ-XAFS).
- Applied the coupled technique to environmental iron mat samples.
Main Results:
- Identified Betaproteobacteria, dominated by IOB, localized within 10 μm of the surface in natural iron mats.
- Synchrotron microprobe analysis revealed short-ordered Fe-O(6) linkages at IOB accumulation sites.
- This specific Fe local structure differs from that found in bulk iron mat samples.
Conclusions:
- The coupled XAFS-FISH technique offers a powerful approach for in situ analysis of biomineralization.
- Provides direct insights into microbe-specific mineral precipitation and geochemical processes.
- Advances understanding of microbial roles in elemental cycling within aquatic environments.
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