Chattopadhyay Suddhashil, Wu Xiao-Lun
Department of Physics and Astronomy, University of Pittsburgh, Pittsburgh, Pennsylvania, USA.
Biophys J. 2009 Mar 4;96(5):2023-8. doi: 10.1016/j.bpj.2008.11.046.
It has been theoretically suggested that when a bacterium swims in a fluid, the disturbance it creates is long-ranged and can influence its locomotion. The contribution of these long-range hydrodynamic interactions to swimming cells is examined herein for a number of bacterial strains with well-defined flagellar geometries. We show experimentally for the first time that long-range hydrodynamic interactions are important for an accurate description of the swimming of a single cell, and the effect is more pronounced for bacteria with a large cell body. The commonly used local resistive force theory assumes a stationary background fluid while ignoring flows induced due to other moving parts of the cell. Although pedagogically attractive, resistive force theory is not generally applicable to experiment.
从理论上讲，有观点认为当细菌在流体中游动时，它所产生的扰动具有长程性，并且会影响其运动。本文针对一些具有明确鞭毛几何形状的细菌菌株，研究了这些长程流体动力相互作用对游动细胞的影响。我们首次通过实验表明，长程流体动力相互作用对于准确描述单细胞的游动很重要，并且对于细胞体较大的细菌，这种影响更为明显。常用的局部阻力理论假定背景流体是静止的，却忽略了细胞其他运动部分所引起的流动。尽管阻力理论在教学上很有吸引力，但它通常并不适用于实验。
