Switching of swimming modes in Magnetospirillium gryphiswaldense

Abstract

The microaerophilic magnetotactic bacterium Magnetospirillum gryphiswaldense swims along magnetic field lines using a single flagellum at each cell pole. It is believed that this magnetotactic behavior enables cells to seek optimal oxygen concentration with maximal efficiency. We analyse the trajectories of swimming M. gryphiswaldense cells in external magnetic fields larger than the earth's field, and show that each cell can switch very rapidly (in < 0.2 s) between a fast and a slow swimming mode. Close to a glass surface, a variety of trajectories was observed, from straight swimming that systematically deviates from field lines to various helices. A model in which fast (slow) swimming is solely due to the rotation of the trailing (leading) flagellum can account for these observations. We determined the magnetic moment of this bacterium using a new method, and obtained a value of (2.0 $\pm$ 0.6) $\times$ $10^{-16}$ Am${}^2$. This value is found to be consistent with parameters emerging from quantitative fitting of trajectories to our model.

arXiv comment27 pages, 7 figures

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• Enhanced diffusion due to active swimmers at a solid surface
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Cited by in corpus (10)

• ESPResSo 4.0 -- An Extensible Software Package for Simulating Soft Matter Systems
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• Lattice-Boltzmann Hydrodynamics of Anisotropic Active Matter
• Magnetic Response of Magnetospirillum Gryphiswaldense
• Actuated rheology of magnetic micro-swimmers suspensions : emergence of motor and brake states
• Controlling stability and transport of magnetic microswimmers by an external field
• Environment-dependent swimming strategy of Magnetococcus marinus under magnetic field
• Long term observation of Magnetospirillum gryphiswaldense in a microfluidic channel
• Experimental determination of the propulsion matrix of the body of helical Magnetospirillum magneticum cells
• Magnetic properties of an individual Magnetospirillum gryphiswaldense cell