Invariance properties of bacterial random walks in complex structures
Invariance properties of bacterial random walks in complex structures
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DOI：
10.1038/s41467-019-10455-y
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发表时间：
2019-06-04
影响因子：
16.6
通讯作者：
Di Leonardo, Roberto
中科院分区：
文献类型：
--
作者：
Frangipane, Giacomo;Vizsnyiczai, Gaszton;Di Leonardo, Roberto
运动细胞经常探索具有高度结构复杂性的自然环境。此外，由于自发的随机重新定向和速度波动，细胞运动本质上也是有噪声的。内部和外部噪声源的相互作用产生了复杂的动态行为，这种行为对细节非常敏感，并且难以定量建模。与这张总体图形成鲜明对比的是，我们表明，游泳细菌在人工复杂微结构内的平均停留时间是通过随机游走的通用不变性特性定量预测的。我们发现，虽然外部形状和内部无序对路径长度和停留时间的分布有显着影响，但相应的平均值受到唯一自由表面与周长比的限制。与直觉相反的是，由于可及表面较低，细菌从障碍物密度较高的结构中逃逸得更快。
Motile cells often explore natural environments characterized by a high degree of structural complexity. Moreover cell motility is also intrinsically noisy due to spontaneous random reorientations and speed fluctuations. This interplay of internal and external noise sources gives rise to a complex dynamical behavior that can be strongly sensitive to details and hard to model quantitatively. In striking contrast to this general picture we show that the mean residence time of swimming bacteria inside artificial complex microstructures is quantitatively predicted by a generic invariance property of random walks. We find that while external shape and internal disorder have dramatic effects on the distributions of path lengths and residence times, the corresponding mean values are constrained by the sole free surface to perimeter ratio. As a counterintuitive consequence, bacteria escape faster from structures with higher density of obstacles due to the lower accessible surface.