Xie Li, Wu Xiao-Lun
Department of Physics and Astronomy, University of Pittsburgh, Pittsburgh, Pennsylvania.
Department of Physics and Astronomy, University of Pittsburgh, Pittsburgh, Pennsylvania.
Biophys J. 2014 Oct 7;107(7):1712-20. doi: 10.1016/j.bpj.2014.07.058.
Bacteria use different motility patterns to navigate and explore natural habitats. However, how these motility patterns are selected, and what their benefits may be, are not understood. In this article, we analyze the effect of motility patterns on a cell's ability to migrate in a chemical gradient and to localize at the top of the gradient, the two most important characteristics of bacterial chemotaxis. We will focus on two motility patterns, run-tumble and run-reverse-flick, that are observed and characterized in enteric bacterium Escherichia coli and marine bacterium Vibrio alginolyticus, respectively. To make an objective comparison, master equations are developed on the basis of microscopic motions of the bacteria. An unexpected yet significant result is that by adopting the run-reverse-flick motility pattern, a bacterium can reduce its diffusivity without compromising its drift in the chemical gradient. This finding is biologically important as it suggests that the motility pattern can improve a microorganism's ability to sequester nutrients in a competitive environment.
细菌利用不同的运动模式在自然栖息地中导航和探索。然而，这些运动模式是如何被选择的，以及它们可能有什么益处，目前尚不清楚。在本文中，我们分析了运动模式对细胞在化学梯度中迁移以及定位在梯度顶端能力的影响，这是细菌趋化性的两个最重要特征。我们将重点关注两种运动模式，即“游动-翻滚”和“游动-反向-轻弹”，它们分别在肠道细菌大肠杆菌和海洋细菌溶藻弧菌中被观察到并进行了特征描述。为了进行客观比较，基于细菌的微观运动建立了主方程。一个意外但重要的结果是，通过采用“游动-反向-轻弹”运动模式，细菌可以在不影响其在化学梯度中漂移的情况下降低其扩散率。这一发现具有生物学重要性，因为它表明运动模式可以提高微生物在竞争环境中获取营养的能力。
