Experiments have shown that wild type P. aeruginosa swarms much faster than rhlAB mutants on 0.4% agar concentration surface. These observations imply that development of a liquid thin film is an important component of the self-organized swarming process. A multiscale model is presented in this paper for studying interplay of key hydrodynamical and biological mechanisms involved in the swarming process of P. aeruginosa. This model combines a liquid thin film equation, convection–reaction–diffusion equations and a cell-based stochastic discrete model. Simulations demonstrate how self-organized swarming process based on the microscopic individual bacterial behavior results in complicated fractal type patterns at macroscopic level. It is also shown that quorum sensing mechanism causing rhamnolipid synthesis and resulting liquid extraction from the substrate lead to the fast swarm expansion. Simulations also demonstrate formation of fingers (tendrils) at the edge of a swarm which have been earlier observed in experiments.

中文翻译：

---

铜绿假单胞菌的多尺度建模

实验表明，在 0.4% 的琼脂浓度表面上，野生型铜绿假单胞菌比 rhlAB 突变体的聚集速度要快得多。这些观察表明，液体薄膜的发展是自组织蜂群过程的重要组成部分。本文提出了一个多尺度模型，用于研究铜绿假单胞菌蜂群过程中涉及的关键流体动力学和生物学机制的相互作用。该模型结合了液体薄膜方程、对流-反应-扩散方程和基于细胞的随机离散模型。模拟展示了基于微观个体细菌行为的自组织蜂群过程如何在宏观水平上产生复杂的分形类型模式。还表明，导致鼠李糖脂合成和从基质中提取液体的群体感应机制导致快速的群体扩张。模拟还展示了在早期实验中观察到的群体边缘的手指（卷须）的形成。