title: Magnetotactic bacteria form magnetite from a phosphate-rich ferric hydroxide via nanometric ferric (oxyhydr)oxide intermediates.
abstract: The iron oxide mineral magnetite (Fe3O4) is produced by various organisms to exploit magnetic and mechanical properties. Magnetotactic bacteria have become one of the best model organisms for studying magnetite biomineralization, as their genomes are sequenced and tools are available for their genetic manipulation. However, the chemical route by which magnetite is formed intracellularly within the so-called magnetosomes has remained a matter of debate. Here we used X-ray absorption spectroscopy at cryogenic temperatures and transmission electron microscopic imaging techniques to chemically characterize and spatially resolve the mechanism of biomineralization in those microorganisms. We show that magnetite forms through phase transformation from a highly disordered phosphate-rich ferric hydroxide phase, consistent with prokaryotic ferritins, via transient nanometric ferric (oxyhydr)oxide intermediates within the magnetosome organelle. This pathway remarkably resembles recent results on synthetic magnetite formation and bears a high similarity to suggested mineralization mechanisms in higher organisms.
authors: Department of Biomaterials, Max Planck Institute of Colloids and Interfaces, 14424 Potsdam, Germany.
authors: Jens
authors: J
authors: Baumgartner
authors: Guillaume
authors: G
authors: Morin
authors: Nicolas
authors: N
authors: Menguy
authors: Teresa
authors: T
authors: Perez Gonzalez
authors: Marc
authors: M
authors: Widdrat
authors: Julie
authors: J
authors: Cosmidis
authors: Damien
authors: D
authors: Faivre
mesh_terms: D005290:Ferric Compounds / Q000378:metabolism; D052203:Ferrosoferric Oxide / Q000378:metabolism*; D058185:Magnetite Nanoparticles / Q000648:ultrastructure; D055944:Magnetosomes / Q000378:metabolism / Q000648:ultrastructure; D042201:Magnetospirillum / Q000378:metabolism* / Q000648:ultrastructure; D017348:Microscopy, Electron, Scanning Transmission; D046529:Microscopy, Electron, Transmission; D010710:Phosphates / Q000378:metabolism; D056928:X-Ray Absorption Spectroscopy
chemical_list: D005290:Ferric Compounds; D058185:Magnetite Nanoparticles; D010710:Phosphates; C000499:ferric oxide; C021024:ferric hydroxide; D052203:Ferrosoferric Oxide
keywords: ferrihydrite; geomagnetism; hematite; nanoparticles; precursors
references: PLoS One. 2011;6(10):e25561
references: 22043287
references: J Struct Biol. 2004 Aug;147(2):166-78
references: 15193645
references: J Comp Neurol. 2003 Apr 14;458(4):350-60
references: 12619070
references: Mol Microbiol. 2012 Aug;85(4):684-99
references: 22716969
references: Free Radic Biol Med. 2008 Mar 15;44(6):921-37
references: 18155672
references: Proc Natl Acad Sci U S A. 2010 Mar 23;107(12):5593-8
references: 20212111
references: Chem Rev. 2008 Nov;108(11):4875-98
references: 18855486
references: Science. 1967 Jun 9;156(3780):1373-5
references: 5610118
references: J Struct Biol. 2009 Apr;166(1):22-31
references: 19116170
references: Nature. 2004 Nov 25;432(7016):508-11
references: 15565156
references: Angew Chem Int Ed Engl. 2007;46(44):8495-9
references: 17902080
references: Nat Mater. 2013 Apr;12(4):310-4
references: 23377292
references: FEMS Microbiol Rev. 2012 Jan;36(1):232-55
references: 22092030
references: Science. 2006 Jan 13;311(5758):242-5
references: 16373532
references: Proc Natl Acad Sci U S A. 2010 Apr 6;107(14):6316-21
references: 20308589
references: Mol Microbiol. 2011 Nov;82(4):818-35
references: 22007638
references: Curr Opin Neurobiol. 2001 Aug;11(4):462-7
references: 11502393
references: Prog Mol Subcell Biol. 2011;52:3-27
references: 21877261
references: Nature. 2011 Jan 13;469(7329):194-7
references: 21228873
references: Science. 2008 Mar 21;319(5870):1635-8
references: 18356516
references: ACS Nano. 2013 Apr 23;7(4):3297-305
references: 23530668
references: J Biol Chem. 2011 Feb 25;286(8):6386-92
references: 21169637
references: Environ Sci Technol. 2007 Jan 1;41(1):166-72
references: 17265943
references: Proc Natl Acad Sci U S A. 2007 Dec 4;104(49):19524-8
references: 18032611
references: Plant Physiol. 1995 Nov;109(3):797-802
references: 8552714
references: Biochemistry. 1990 Jan 9;29(1):259-64
references: 2322545
references: J Synchrotron Radiat. 2005 Jul;12(Pt 4):537-41
references: 15968136
references: Science. 2004 Nov 12;306(5699):1161-4
references: 15539597
references: Proc Natl Acad Sci U S A. 2012 Mar 6;109(10):3699-704
references: 22343283