Petroff Alexander P, Hernandez Julia, Kelin Vladislav, Radchenko-Hannafin Nina
Department of Physics, Clark University, Worcester Massachusetts, United States.
Elife. 2025 Sep 16;14:RP104797. doi: 10.7554/eLife.104797.
Magnetotactic bacteria swim along geomagnetic field lines to navigate the pore spaces of water-saturated sediment. To understand the physical basis for efficient navigation in confined geometries, we observe the motion of multicellular magnetotactic bacteria through an artificial pore space under an applied magnetic field. Magnetotaxis is fastest when bacteria swim a distance that is of order the pore size in the time required to align with the applied field. A model-in which bacteria deterministically align with the magnetic field and randomly scatter off boundaries-predicts the observed non-monotonic relationship between the drift velocity and applied magnetic field and the value of the maximum drift velocity. A comparison of the reported values of the magnetic moments, swimming speeds, and hydrodynamic mobilities across diverse magnetotactic bacteria reveals that these variables covary such that the average speed of magnetotaxis of each species is close to optimal for its natural environment.
趋磁细菌沿着地磁场线游动，以在水饱和沉积物的孔隙空间中导航。为了理解在受限几何结构中高效导航的物理基础，我们在施加磁场的情况下观察多细胞趋磁细菌在人工孔隙空间中的运动。当细菌游动的距离在与施加磁场对齐所需的时间内达到孔径量级时，趋磁速度最快。一个模型——细菌确定性地与磁场对齐并随机从边界散射——预测了观察到的漂移速度与施加磁场之间的非单调关系以及最大漂移速度的值。对不同趋磁细菌所报道的磁矩、游动速度和流体动力学迁移率值的比较表明，这些变量相互协变，使得每个物种的趋磁平均速度接近其自然环境的最佳速度。
