Institute of Electrical Engineering, Chinese Academy of Sciences, Beijing, 100190, China.
Appl Microbiol Biotechnol. 2011 Apr;90(1):269-75. doi: 10.1007/s00253-010-3017-1. Epub 2010 Dec 7.
Magnetotactic bacteria (MTB) can rapidly relocate to optimal habitats by magneto-aerotaxis. Little is known about MTB phototaxis, a response that might also aid navigation. In this study, we analyzed the relationship between phototaxis and magnetotaxis in Magnetospirillum magneticum strain AMB-1. Magnotactic AMB-1 cells migrated toward light, and migration increased with higher light intensity. This response was independent of wavelength, as AMB-1 cells migrated equally toward light from 400 to 750 nm. When AMB-1 cells were exposed to zero magnetic fields or to 0.2 mT magnetic fields that were opposite or orthogonal to the light beam, cells still migrated toward the light, indicating that phototaxis was independent of magnetotaxis. The R(mag) value and coercive force (H(c)) of AMB-1 increased when the bacteria were illuminated for 20 h, consistent with an increase in magnetosome synthesis or in magnetosome-containing cells. These results demonstrated that the M. magneticum AMB-1 responded to light as well as other environmental factors. To our knowledge, this is the first report of phototactic behavior in the bacteria of Magnetospirillum.
趋磁细菌 (MTB) 可以通过磁趋化性和趋化性迅速迁移到最佳栖息地。关于 MTB 的趋光性知之甚少，这种反应也可能有助于导航。在这项研究中，我们分析了趋磁螺旋菌菌株 AMB-1 中趋光性和趋磁性之间的关系。趋磁 AMB-1 细胞向光迁移，迁移随着光强度的增加而增加。这种反应与波长无关，因为 AMB-1 细胞对 400 到 750nm 的光的迁移率相同。当 AMB-1 细胞暴露于零磁场或与光束相反或正交的 0.2mT 磁场中时，细胞仍然向光迁移，表明趋光性独立于趋磁性。当细菌被照射 20 小时时，AMB-1 的 R(mag) 值和矫顽力 (H(c)) 增加，这与磁小体合成或含有磁小体的细胞增加一致。这些结果表明，M. magneticum AMB-1 对光以及其他环境因素有反应。据我们所知，这是首次报道趋磁螺旋菌的趋光行为。
