Misalignment between the magnetic dipole moment and the cell axis in the magnetotactic bacterium Magnetospirillum magneticum AMB-1
Autor: | Murtuza Rajkotwala, Solomon Barkley, Lucas Le Nagard, Dennis A. Bazylinski, Adam P. Hitchcock, Cécile Fradin, Liu Yu |
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Rok vydání: | 2019 |
Předmět: |
Physics
0303 health sciences education.field_of_study Magnetotactic bacteria Magnetic moment Condensed matter physics 030306 microbiology Population Magnetosome Biophysics Rotational diffusion Cell Biology equipment and supplies Biomagnetism Quantitative Biology::Cell Behavior Magnetic field 03 medical and health sciences Magnetic Fields Structural Biology Magnetotaxis Magnetospirillum education human activities Molecular Biology 030304 developmental biology |
Zdroj: | Physical biology. 16(6) |
ISSN: | 1478-3975 |
Popis: | While most quantitative studies of the motion of magnetotactic bacteria rely on the premise that the cells' magnetic dipole moment is aligned with their direction of motility, this assumption has so far rarely been challenged. Here we use phase contrast microscopy to detect the rotational diffusion of non-motile cells of Magnetospirillum magneticum AMB-1 around their magnetic moment, showing that in this species the magnetic dipole moment is, in fact, not exactly aligned with the cell body axis. From the cell rotational trajectories, we are able to infer the misalignment between cell magnetic moment and body axis with a precision of better than 1°, showing that it is, on average, 6°, and can be as high as 20°. We propose a method to correct for this misalignment, and perform a non-biased measurement of the magnetic moment of single cells based on the analysis of their orientation distribution. Using this correction, we show that magnetic moment strongly correlates with cell length. The existence of a range of misalignments between magnetic moment and cell axis in a population implies that the orientation and trajectories of magnetotactic bacteria placed in external magnetic fields is more complex than generally assumed, and might show some important cell-to-cell differences. |
Databáze: | OpenAIRE |
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