Self-transport of swimming bacteria is impaired by porous microstructure
Self-transport of swimming bacteria is impaired by porous microstructure
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DOI：
10.1038/s42005-023-01136-w
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发表时间：
2023-01-24
影响因子：
5.5
通讯作者：
Guasto, Jeffrey S.
中科院分区：
文献类型：
--
作者：
Dehkharghani, Amin;Waisbord, Nicolas;Guasto, Jeffrey S.
运动性是细菌在多孔环境中生存的基本策略，在多孔环境中，它们介导静止湿地和沉积物中的基本生态地球化学过程。然而，在多孔介质的受限间隙中调节自运输的机制的全面理解是缺乏的，并且确定细胞和固体基质表面之间的相互作用变得至关重要。在这里，我们通过一系列具有广泛变化的几何形状的微流体多孔介质精确地跟踪细菌（海洋磁球菌）的运动，并显示固体表面的连续散射事件如何使细胞运动去相关。有序与无序介质在短范围内影响细胞的运动性，但它们的大规模运输特性由其持续运动性的截止来调节。一个有效的平均自由程被建立为控制细胞运输的关键几何参数，我们实现了一个理论模型，普遍预测有效的细胞扩散的不同的几何形状在这里研究。这些结果有助于我们理解游泳细胞的物理生态学，以及它们在停滞多孔介质中的环境和健康危害中的作用。细菌通常居住在复杂的微环境中，它们必须有效地导航。本文提出了一种实验研究细菌的运动和分散在有序和无序阵列的障碍物作为一个现实的多孔介质的代理，并建立了细菌的平均自由程作为细菌导航的决定因素。
Motility is a fundamental survival strategy of bacteria to navigate porous environments, where they mediate essential biogeochemical processes in quiescent wetlands and sediments. However, a comprehensive understanding of the mechanisms regulating self-transport in the confined interstices of porous media is lacking, and determining the interactions between cells and surfaces of the solid matrix becomes paramount. Here, we precisely track the movement of bacteria (Magnetococcus marinus) through a series of microfluidic porous media with broadly varying geometries and show how successive scattering events from solid surfaces decorrelate cell motion. Ordered versus disordered media impact the cells' motility over short ranges, but their large-scale transport properties are regulated by the cutoff of their persistent motility. An effective mean free path is established as the key geometrical parameter controlling cell transport, and we implement a theoretical model that universally predicts the effective cell diffusion for the diverse geometries studied here. These results aid in our understanding of the physical ecology of swimming cells, and their role in environmental and health hazards in stagnant porous media.Bacteria often reside within complex microenvironments through which they have to navigate efficiently. This paper presents an experimental study of bacterial motility and dispersion within ordered and disordered arrays of obstacles as a proxy to a realistic porous medium and established a bacterial mean free path as the determining factor for bacterial navigation.