Confinement and activity regulate bacterial motion in porous media
Confinement and activity regulate bacterial motion in porous media
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DOI：
10.1039/c9sm01735f
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发表时间：
2019-12-28
期刊：
影响因子：
3.4
通讯作者：
Datta, Sujit S.
中科院分区：
文献类型：
--
作者：
Bhattacharjee, Tapomoy;Datta, Sujit S.
了解细菌如何在多孔介质中移动对于医疗保健、农业、环境修复和化学传感方面的应用至关重要。最近的研究表明，在均匀介质中通过跑动和翻滚动力学移动的大肠杆菌，当被限制在无序的多孔介质中时，表现出一种新的运动形式：跳跃和捕获运动，其中细胞执行快速、定向的跳跃，其间穿插着缓慢的、非定向的捕获间隔。在这里，我们使用直接可视化来阐明这些过程是如何依赖于孔隙尺度的限制和细胞活动的。我们发现，跳跃是由孔尺度限制决定的，并且与细胞活动无关；相反，捕获是由孔尺度限制和细胞活动之间的竞争决定的，正如熵捕获模型所预测的那样。因此，这些结果有助于阐明调节细菌在多孔介质中运动的因素，并有助于开发在不同环境中运动的新模型。
Understanding how bacteria move in porous media is critical to applications in healthcare, agriculture, environmental remediation, and chemical sensing. Recent work has demonstrated that E. coli, which moves by run-and-tumble dynamics in a homogeneous medium, exhibits a new form of motility when confined in a disordered porous medium: hopping-and-trapping motility, in which cells perform rapid, directed hops punctuated by intervals of slow, undirected trapping. Here, we use direct visualization to shed light on how these processes depend on pore-scale confinement and cellular activity. We find that hopping is determined by pore-scale confinement, and is independent of cellular activity; by contrast, trapping is determined by the competition between pore-scale confinement and cellular activity, as predicted by an entropic trapping model. These results thus help to elucidate the factors that regulate bacterial motion in porous media, and could help aid the development of new models of motility in heterogeneous environments.