Erglis Kaspars, Wen Qi, Ose Velta, Zeltins Andris, Sharipo Anatolijs, Janmey Paul A, Cēbers Andrejs
University of Latvia, Zellu, Latvia.
Biophys J. 2007 Aug 15;93(4):1402-12. doi: 10.1529/biophysj.107.107474. Epub 2007 May 25.
The dynamics of the motile magnetotactic bacterium Magnetospirillum gryphiswaldense in a rotating magnetic field is investigated experimentally and analyzed by a theoretical model. These elongated bacteria are propelled by single flagella at each bacterial end and contain a magnetic filament formed by a linear assembly of approximately 40 ferromagnetic nanoparticles. The movements of the bacteria in suspension are analyzed by consideration of the orientation of their magnetic dipoles in the field, the hydrodynamic resistance of the bacteria, and the propulsive force of the flagella. Several novel features found in experiments include a velocity reversal during motion in the rotating field and an interesting diffusive wandering of the trajectory curvature centers. A new method to measure the magnetic moment of an individual bacterium is proposed based on the theory developed.
通过实验研究了趋磁运动细菌格氏嗜盐碱螺旋菌在旋转磁场中的动力学，并采用理论模型进行分析。这些细长的细菌在每个细菌末端由单个鞭毛推动，并包含由大约40个铁磁纳米颗粒线性组装形成的磁丝。通过考虑细菌磁偶极子在磁场中的取向、细菌的流体动力学阻力以及鞭毛的推进力，分析了悬浮液中细菌的运动。实验中发现的几个新特征包括在旋转磁场中运动时的速度反转以及轨迹曲率中心有趣的扩散漂移。基于所发展的理论，提出了一种测量单个细菌磁矩的新方法。
