Microbial competition in porous environments can select against rapid biofilm growth
Microbial competition in porous environments can select against rapid biofilm growth
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DOI：
10.1073/pnas.1525228113
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发表时间：
2017-01-10
影响因子：
11.1
通讯作者：
Durham, William M.
中科院分区：
文献类型：
--
作者：
Coyte, Katharine Z.;Tabuteau, Herve;Durham, William M.
微生物通常生活在称为生物膜的密集群落中，其中菌株和物种之间的竞争对于进化和群落功能都是至关重要的。虽然生物膜通常存在于类似土壤的多孔环境中，但微生物相互作用的研究主要集中在平坦表面上生长的生物膜上。在这里，我们使用微流体实验，机械模型和博弈论来研究多孔介质流体力学如何介导细菌基因型之间的竞争。我们的实验揭示了生活在多孔环境中的微生物菌株所面临的一个根本挑战：快速形成生物膜的细胞往往会阻止它们进入流体流动，并将资源重新导向竞争对手。为了了解这些动态如何影响细菌生长速率的演变，我们耦合了一个模型的流生物膜相互作用的博弈论分析。这项研究表明，竞争基因型之间的流体动力学相互作用产生了一个进化上稳定的生长速率，这与典型的实验室实验中观察到的形成鲜明对比：生物膜内的细胞可以通过生长得更慢而胜过其他基因型。我们的工作表明，流体动力学可以深刻地影响细菌如何在多孔环境中竞争和进化，而多孔环境是大多数细菌生活的栖息地。
Microbes often live in dense communities called biofilms, where competition between strains and species is fundamental to both evolution and community function. Although biofilms are commonly found in soil-like porous environments, the study of microbial interactions has largely focused on biofilms growing on flat, planar surfaces. Here, we use microfluidic experiments, mechanistic models, and game theory to study how porous media hydrodynamics can mediate competition between bacterial genotypes. Our experiments reveal a fundamental challenge faced by microbial strains that live in porous environments: cells that rapidly form biofilms tend to block their access to fluid flow and redirect resources to competitors. To understand how these dynamics influence the evolution of bacterial growth rates, we couple a model of flow-biofilm interaction with a game theory analysis. This investigation revealed that hydrodynamic interactions between competing genotypes give rise to an evolutionarily stable growth rate that stands in stark contrast with that observed in typical laboratory experiments: cells within a biofilm can outcompete other genotypes by growing more slowly. Our work reveals that hydrodynamics can profoundly affect how bacteria compete and evolve in porous environments, the habitat where most bacteria live.