Light effects on the multicellular magnetotactic prokaryote ‘ass="a-plus-plus">Candidatus Magnetoglobus multicellularis’ are cancelled by radiofrequency fields: the involvement of radical pair mechanisms
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- 作者：Roger Duarte de Melo ; Daniel Acosta-Avalos
- 关键词：Magnetotaxis ; Multicellular magnetotactic prokaryote ; Light ; dependent ; Photokinesis ; Candidatus Magnetoglobus multicellularis ; Radical pair mechanism
- 刊名：Antonie van Leeuwenhoek
- 出版年：2017
- 出版时间：February 2017
- 年：2017
- 卷：110
- 期：2
- 页码：177-186
- 全文大小：
- 刊物类别：Biomedical and Life Sciences
- 刊物主题：Microbiology; Medical Microbiology; Plant Sciences; Soil Science & Conservation;
- 出版者：Springer International Publishing
- ISSN：1572-9699
- 卷排序：110
文摘
‘ass="EmphasisTypeItalic ">Candidatus Magnetoglobus multicellularis’ is the most studied multicellular magnetotactic prokaryote. It presents a light-dependent photokinesis: green light decreases the translation velocity whereas red light increases it, in comparison to blue and white light. The present article shows that radio-frequency electromagnetic fields cancel the light effect on photokinesis. The frequency to cancel the light effect corresponds to the Zeeman resonance frequency (DC magnetic field of 4 Oe and radio-frequency of 11.5 MHz), indicating the involvement of a radical pair mechanism. An analysis of the orientation angle relative to the magnetic field direction shows that radio-frequency electromagnetic fields disturb the swimming orientation when the microorganisms are illuminated with red light. The analysis also shows that at low magnetic fields (1.6 Oe) the swimming orientation angles are well scattered around the magnetic field direction, showing that magnetotaxis is not efficiently in the swimming orientation to the geomagnetic field. The results do not support cryptochrome as being the responsible chromophore for the radical pair mechanism and perhaps two different chromophores are necessary to explain the radio-frequency effects.