The European Physical Journal E ( IF 1.8 ) Pub Date : 2021-03-15 , DOI: 10.1140/epje/s10189-021-00009-w Theresa Jakuszeit 1 , James Lindsey-Jones 1 , François J Peaudecerf 2 , Ottavio A Croze 1, 3
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Abstract
Bacteria can chemotactically migrate up attractant gradients by controlling run-and-tumble motility patterns. In addition to this well-known chemotactic behaviour, several soil and marine bacterial species perform chemokinesis; they adjust their swimming speed according to the local concentration of chemoeffector, with higher speed at higher concentration. A field of attractant then induces a spatially varying swimming speed, which results in a drift towards lower attractant concentrations—contrary to the drift created by chemotaxis. Here, to explore the biological benefits of chemokinesis and investigate its impact on the chemotactic response, we extend a Keller–Segel-type model to include chemokinesis. We apply the model to predict the dynamics of bacterial populations capable of chemokinesis and chemotaxis in chemoeffector fields inspired by microfluidic and agar plate migration assays. We find that chemokinesis combined with chemotaxis not only may enhance the population response with respect to pure chemotaxis, but also modifies it qualitatively. We conclude presenting predictions for bacteria around dynamic finite-size nutrient sources, simulating, e.g. a marine particle or a root. We show that chemokinesis can reduce the measuring bias that is created by a decaying attractant gradient.
Graphic abstract
中文翻译：
具有趋化性和趋化作用的细菌的迁移和积累
抽象的
细菌可以通过控制奔跑和翻滚的运动模式来趋化地沿引诱剂梯度迁移。除了这种众所周知的趋化行为外，一些土壤和海洋细菌物种也具有趋化作用。它们根据局部化学效应物的浓度来调整游泳速度，浓度越高，游动速度越快。然后，引诱剂场会引起空间变化的游动速度，从而导致向较低引诱剂浓度的漂移，这与趋化性产生的漂移相反。在这里，为了探索趋化作用的生物学益处并研究其对趋化反应的影响，我们扩展了凯勒-塞格尔型模型以包括趋化作用。受微流体和琼脂板迁移测定的启发，我们应用该模型来预测能够在化学效应器场中趋化和趋化的细菌群体的动态。我们发现趋化作用与趋化作用相结合不仅可以增强相对于纯趋化作用的群体反应，而且还可以定性地改变它。最后，我们提出了对动态有限尺寸营养源周围细菌的预测，模拟海洋颗粒或根。我们表明，趋化作用可以减少由衰减的吸引剂梯度产生的测量偏差。
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