A magnetotactic bacterium capable of magnetic sensing

Area of Science:

• Microbiology
• Biophysics
• Magnetoreception

Background:

• Magnetosensitive organisms actively respond to magnetic field features.
• Magnetosensing in higher organisms involves cryptochromes or magnetic particles.
• Magnetotactic bacteria were believed to passively align with magnetic fields.

Purpose of the Study:

• To investigate magnetosensing capabilities in magnetotactic bacteria.
• To determine the mechanism of magnetosensing in magnetotactic bacteria.

Main Methods:

• Cultivation of magnetotactic bacterium SS-5.
• Measurement of bacterial swimming speed under physiological and canceled magnetic fields.
• Assessment of response to varying illumination wavelengths.
• Disruption of the bacterial magnetic backbone.

Main Results:

• Magnetotactic bacterium SS-5 exhibits active magnetosensing.
• Bacteria swam faster in a physiological magnetic field than in a canceled field.
• The response was independent of illumination wavelength.
• Disrupting the magnetic backbone altered the magnetosensing response.
• The response intensity correlated with relative magnetic field changes, similar to Weber-Fechner laws.

Conclusions:

• Magnetotactic bacteria possess active magnetosensing abilities.
• Magnetosensing in these bacteria likely involves magnetomechanical signal transduction along the magnetotactic filament.
• This bacterial magnetosensing mechanism resembles other forms of taxes, responding to relative magnetic field intensity changes.