Study type: Medical/biological study (experimental study)

Effects of pulsed magnetic field on the formation of magnetosomes in the Magnetospirillum sp. strain AMB-1. med./bio.

Published in: Bioelectromagnetics 2010; 31 (3): 246-251

Aim of study (acc. to author)

To study the effects of a 50 Hz, 2 mT pulsed magnetic field on the formation of magnetosomes in Magnetospirillum sp. strain AMB-1.

Background/further details

Magnetotactic bacteria are a diverse group of microorganisms which possess one or more chains of magnetosomes (containing magnetite). These bacteria are able to use the geomagnetic field for direction sensing, thus providing a simple model for the study of magnetite-based magnetoreception.
56 bacterial samples were tested (28 were exposed and 28 samples were sham-exposed).

Endpoint

Exposure

Exposure Parameters
Exposure 1: 50 Hz
Modulation type: pulsed
Exposure duration: continuous for 2 h, 4 h, 8 h, 12 h, 16 h or 24 h

Exposure 1

Main characteristics
Frequency 50 Hz
Type
Exposure duration continuous for 2 h, 4 h, 8 h, 12 h, 16 h or 24 h
Modulation
Modulation type pulsed
Duty cycle 50 %
Pulse type rectangular
Exposure setup
Exposure source
Setup 400 mm long solenoid coil with a diamter of 200 mm; samples placed inside the solenoid
Sham exposure A sham exposure was conducted.
Parameters
Measurand Value Type Method Mass Remarks
magnetic flux density 2 mT maximum measured - at the center of the solenoid

Exposed system:

Methods Endpoint/measurement parameters/methodology

Investigated system:
Time of investigation:
  • during exposure
  • after exposure

Main outcome of study (acc. to author)

The data showed that the cellular magnetism of the bacterial culture significantly increased while the growth of cells remained unaffected after exposure. After exposure, the number of magnetic particles per cell was increased by about 15% and slightly enhanced ratios of magnetic particles of superparamagnetic property (size <20 nm) and mature magnetosomes (size >50 nm) were found. In addition, the intracellular iron accumulation slightly increased after pulsed magnetic field exposure.
The authors conclude that 50 Hz, 2 mT pulsed magnetic field exposure affect the formation of magnetosomes in Magnetospirillum sp. strain AMB-1. The pulsed magnetic field could increase cellular magnetism and the number of magnetic particles and affected the distribution of magnetosomes.

Study character:

Study funded by

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