Magnetite (Fe3O4) magnetosomes
Strain MV-1
Elongated magnetosomes in strain MV-1.
Magnetosomes extracted from MV-1 cells (magnetosomes approx 60x35 nm).
MV-1 magnetsome.
Strain MS-1 (Magnetospirillum magnetotacticum)
MS-1 cell with magnetosomes (Bar = 1 micron).
Thin section of MS-1. Magnetsomes are approx. 45 nm in diameter.
MS-1 magnetosomes (45 nm) (B. Devouard).
MS-1 magnetosomes (45 nm) (B. Devouard).
Strain MV-4
MV-4 cell with magnetosomes and polyphosphate and sulfur granules.
Strain MC-1
MC-1 cell. FB=flagellar bundles; M=magnetsosomes (Frankel et al., 1997)
Magnetsomes from several cell types
Magnetosomes in a) Magnetospirillum magnetotacticum; b)
strain MV-1; c) strain MV-4 (arrows indicate twinning); d) strain MC-1
(Devouard et al., 1998).
Magnetosomes in a) strrain MV-1; b) strain MC-1; c) unidentified rod-shaped
marine bacterium.
M. bavaricum
Magnetotactic bacterium from the Chiemsee, Bavaria, Germany (Biomagnetism
Group, University of Munich).
Dark blobs are sulfur granules.
Magnetic microstructure by electron holography
Magnetic flux lines associated with a MS-1 cell, superposed on the magnetosome
chain (magnetosomes shown in white) (Dunin-Borkowski et al., 1998)
Some of the magnetosome crystal habits found in magnetotactic bacteria. Cuboctahedra (lower left) are found in both magnetite and iron sulfide magnetosomes. Two elongated habits (upper right and upper left) are found in magnetite magnetosomes. The lower right elongated habit is found in iron sulfide magnetosomes.
Ideal crystal habit for many inorganic magnetites.
Greigite (Fe3S4) magnetosomes.
A) A multicellular magnetotactic bacterium known as the MMP or "mulberry" which is commonly found in marine or brackish sulfidic environments. It consists of approx. 20 cells each of which contains greigite magnetosomes. The cell has fallen open on the microscope grid showing the magnetosomes in a number of individual cells.
B) An unidentified magnetotactic rod containing greigite magnetosomes
Unidentified rods containing greigite magnetosomes.
Electron diffraction patterns from single greigite magnetosomes (Posfai
et al., 1998).
