Hydrodynamic attraction of bacteria to gas and liquid interfaces
Hydrodynamic attraction of bacteria to gas and liquid interfaces
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DOI：
10.1103/physreve.100.062605
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发表时间：
2019-12-20
影响因子：
2.4
通讯作者：
Ardekani, Arezoo M.
中科院分区：
文献类型：
--
作者：
Ahmadzadegan, Adib;Wang, Shiyan;Ardekani, Arezoo M.
在界面附近，由于游动引起的界面流体动力学，游动微生物（例如细菌）的分布与惰性胶体颗粒不同。在这项工作中，我们使用非翻滚鞭毛细菌大肠杆菌来研究气体和液体界面附近的细胞分布，并将其与固体壁的情况进行比较。对于低粘度比（例如气体界面），我们观察到与液体和固体表面附近相比更强的细胞积累。这与已知的理论预测相矛盾。因此，我们开发了一个基于布朗动力学的模型，包括流体动力学效应和细菌与界面之间的短程物理化学相互作用。该模型解释了我们的实验结果，并可以预测清洁和表面活性剂污染界面附近的细胞分布。通过考虑高阶奇点，这项研究有助于解释细菌的方向、轨迹和细胞密度。
Near an interface, the distribution of swimming microorganisms such as bacteria is distinguished from inert colloidal particles because of the interfacial hydrodynamics induced by swimming. In this work, we use nontumbling flagellated bacteria, Escherichia coli, to study cell distribution near gas and liquid interfaces and compare it to the case of a solid wall. For low-viscosity ratios such as gas interfaces, we observe a stronger cell accumulation compared to that near liquid and solid surfaces. This contradicts known theoretical predictions. Therefore, we develop a model based on Brownian dynamics, including hydrodynamic effects and short-range physiochemical interactions between bacteria and interfaces. This model explains our experimental findings and can predict cell distribution near clean and surfactant-contaminated interfaces. By considering higher order singularities, this study helps explain bacteria orientation, trajectories, and cell density.