Magnetic-field induced rotation of magnetosome chains in silicified magnetotactic bacteria

Sci Rep. 2018 May 16;8(1):7699. doi: 10.1038/s41598-018-25972-x.


Understanding the biological processes enabling magnetotactic bacteria to maintain oriented chains of magnetic iron-bearing nanoparticles called magnetosomes is a major challenge. The study aimed to constrain the role of an external applied magnetic field on the alignment of magnetosome chains in Magnetospirillum magneticum AMB-1 magnetotactic bacteria immobilized within a hydrated silica matrix. A deviation of the chain orientation was evidenced, without significant impact on cell viability, which was preserved after the field was turned-off. Transmission electron microscopy showed that the crystallographic orientation of the nanoparticles within the chains were preserved. Off-axis electron holography evidenced that the change in magnetosome orientation was accompanied by a shift from parallel to anti-parallel interactions between individual nanocrystals. The field-induced destructuration of the chain occurs according to two possible mechanisms: (i) each magnetosome responds individually and reorients in the magnetic field direction and/or (ii) short magnetosome chains deviate in the magnetic field direction. This work enlightens the strong dynamic character of the magnetosome assembly and widens the potentialities of magnetotactic bacteria in bionanotechnology.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Magnetic Fields*
  • Magnetosomes / chemistry
  • Magnetosomes / metabolism*
  • Magnetospirillum / growth & development*
  • Magnetospirillum / metabolism*
  • Silicon Dioxide / chemistry*


  • Silicon Dioxide