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Updated: Nov 11, 2025
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Growing Magnetotactic Bacteria of the Genus Magnetospirillum: Strains MSR-1, AMB-1 and MS-1
Published on: October 17, 2018
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Stokesian dynamics simulations of a magnetotactic bacterium
Sarah Mohammadinejad1,2,3, Damien Faivre4,5, Stefan Klumpp6,7
1Institute for the Dynamics of Complex Systems, University of Göttingen, Friedrich-Hund-Platz 1, 37077, Göttingen, Germany. sarah.mohammadinejad@phys.uni-goettingen.de.
The European Physical Journal. E, Soft Matter
|March 24, 2021
Summary
Magnetotactic bacteria (MTB) use flagella for propulsion. Simulations reveal two U-turn regimes based on magnetic field strength, impacting swimming dynamics and flagellar deformation. Inclined magnetic moments create double helical paths.
Area of Science:
- Biophysics
- Microbiology
- Fluid Dynamics
Background:
- Bacteria exhibit unique swimming behaviors governed by low-Reynolds number hydrodynamics.
- Magnetotactic bacteria (MTB) possess magnetic properties enabling directed movement.
- Understanding MTB propulsion and steering is crucial for microbial locomotion studies.
Purpose of the Study:
- To investigate magnetically steered swimming of single-flagellated MTB using simulations.
- To analyze U-turn motion dynamics following magnetic field reversals.
- To explore the impact of magnetic moment inclination on swimming trajectories and velocity.
Main Methods:
- Employed Stokesian dynamics simulations for modeling MTB.
- Incorporated cell body, helical flagellum, magnetic dipole moment, and motor rotation.
- Accounted for flagellar elasticity, magnetic, and hydrodynamic interactions.
Main Results:
- Identified two distinct U-turn regimes (weak and strong fields) with characteristic time scales.
- Observed flagellar deformation in the strong-field regime and cell body/magnetic moment dominance in weak fields.
- Simulated double helical trajectories for inclined magnetic moments, with velocity reduction at large inclinations.
Conclusions:
- Swimming velocity is dependent on model parameters, including magnetic field strength and flagellar properties.
- U-turn dynamics are governed by either magnetic relaxation or flagellar turning, depending on field strength.
- Magnetic moment inclination significantly affects swimming, particularly at large angles, potentially indicating alternative propulsion mechanisms.
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