Geometric effects induce anomalous size-dependent active transport in structured environments
Geometric effects induce anomalous size-dependent active transport in structured environments
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DOI：
10.1103/physrevfluids.7.l071101
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发表时间：
2022-07-11
影响因子：
2.7
通讯作者：
Liu, Bin
中科院分区：
文献类型：
--
作者：
Chopra, Pooja;Quint, David;Liu, Bin
主动自我推进系统中不同个体之间的结构化环境中运输效率的差异既难以研究，也知之甚少。在这里，我们研究了非翻滚大肠杆菌菌株通过周期性柱阵列的运输，这是一种具有内在尺寸变化但速度相当均匀的活性物质原型。我们表明，长期运输从较短细胞的捕获主导状态转变为较长细胞的分散状态，超过由柱阵列几何形状设定的临界细菌尺寸。通过实验和建模的结合，我们表明这种异常的尺寸依赖性是由于附近的柱子引起的较长细胞的捕获逸出率的提高而引起的。我们的结果表明，几何效应可以导致尺寸成为结构化环境中运输的敏感调节旋钮，通常对活性物质系统具有影响，特别是对细菌对结构化栖息地的形态适应、群落的空间结构以及抗生物污损材料的设计具有影响。
The variations of transport efficiency in structured environments between distinct indi-viduals in actively self-propelled systems are both hard to study and poorly understood. Here, we study the transport of a nontumbling Escherichia coli strain, an active-matter archetype with intrinsic size variation but fairly uniform speed, through a periodic pillar ar-ray. We show that long-term transport switches from a trapping dominated state for shorter cells to a much more dispersive state for longer cells above a critical bacterial size set by the pillar array geometry. Using a combination of experiments and modeling, we show that this anomalous size dependence arises from an enhancement of the escape rate from trapping for longer cells caused by nearby pillars. Our results show that geometric effects can lead to size being a sensitive tuning knob for transport in structured environments, with implications in general for active matter systems and, in particular, for the morphological adaptation of bacteria to structured habitats, spatial structuring of communities, and for antibiofouling materials design.