Mechanically Driven Growth of Quasi-Two-Dimensional Microbial Colonies
Mechanically Driven Growth of Quasi-Two-Dimensional Microbial Colonies
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DOI：
10.1103/physrevlett.111.168101
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发表时间：
2013-10-14
影响因子：
8.6
通讯作者：
Waclaw, B.
中科院分区：
文献类型：
--
作者：
Farrell, F. D. C.;Hallatschek, O.;Waclaw, B.
我们研究在固体基质上生长的非运动的杆状细菌菌落。在我们的模型中，细菌纯粹是机械地相互作用，在生长过程中相互推开，并消耗扩散的营养物质。我们表明，机械相互作用控制着前进锋面的速度和形状，这导致了现有的Fisher-Kolmogorov模型无法捕捉的特征。特别是，我们发现速度取决于细菌的弹性模量或它们对表面的粘性。有趣的是，我们预测一个不可压缩的严格二维群体的半径不能随时间线性增长，除非它发展出分支。重要的是，机械相互作用也可以解释在实验室中经常观察到的圆形和分支菌落之间的非平衡转变。
We study colonies of nonmotile, rod-shaped bacteria growing on solid substrates. In our model, bacteria interact purely mechanically, by pushing each other away as they grow, and consume a diffusing nutrient. We show that mechanical interactions control the velocity and shape of the advancing front, which leads to features that cannot be captured by established Fisher-Kolmogorov models. In particular, we find that the velocity depends on the elastic modulus of bacteria or their stickiness to the surface. Interestingly, we predict that the radius of an incompressible, strictly two-dimensional colony cannot grow linearly in time, unless it develops branches. Importantly, mechanical interactions can also account for the nonequilibrium transition between circular and branching colonies, often observed in the lab.