Bacterial swimming and oxygen transport near contact lines
Bacterial swimming and oxygen transport near contact lines
复制标题
DOI：
10.1073/pnas.0406724102
复制
发表时间：
2005-02-15
影响因子：
11.1
通讯作者：
Goldstein, RE
中科院分区：
文献类型：
--
作者：
Tuval, I;Cisneros, L;Goldstein, RE
好氧细菌通常生活在固体-空气-水接触线附近的薄流体层中，其中趋化性，代谢和细胞-细胞信号传导的生物学与浮力，扩散和混合的物理学密切相关。使用的几何形状的一个无柄滴，我们证明了在枯草芽孢杆菌的悬浮液中的自组织产生的持久的流体动力学漩涡，陷阱附近的接触线的细胞。从向上的趋氧性和向下的重力强迫，这些动态有关的抵制效应在沉积和定量解释的数学模型，包括氧的扩散和消耗，趋化性，粘性流体动力学。的旋涡被示出，以平流增强吸收到悬浮液中的氧气，和楔形的几何形状导致在接触线附近的趋化动力学的奇异性。
Aerobic bacteria often live in thin fluid layers near solid-air-water contact lines, in which the biology of chemotaxis, metabolism, and cell-cell signaling is intimately connected to the physics of buoyancy, diffusion, and mixing. Using the geometry of a sessile drop, we demonstrate in suspensions of Bacillus subtilis the self-organized generation of a persistent hydrodynamic vortex that traps cells near the contact line. Arising from upward oxygentaxis and downward gravitational forcing, these dynamics are related to the Boycott effect in sedimentation and are explained quantitatively by a mathematical model consisting of oxygen diffusion and consumption, chemotaxis, and viscous fluid dynamics. The vortex is shown to advectively enhance uptake of oxygen into the suspension, and the wedge geometry leads to a singularity in the chemotactic dynamics near the contact line.