Laminar flow around corners triggers the formation of biofilm streamers
Laminar flow around corners triggers the formation of biofilm streamers
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DOI：
10.1098/rsif.2010.0096
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发表时间：
2010-09-06
影响因子：
3.9
通讯作者：
Stone, Howard A.
中科院分区：
文献类型：
--
作者：
Rusconi, Roberto;Lecuyer, Sigolene;Stone, Howard A.
细菌生物膜对医学、工业和生态学有着巨大的影响。这些微生物群落通常被认为粘附在表面或界面上。然而，在自然生态系统中经常观察到悬浮的丝状生物膜或飘带，它们通过增强营养物质的运输和悬浮颗粒的保留而发挥着至关重要的作用。最近对河边水槽和实验室流动池的研究假设与湍流环境存在联系。然而，流体动力学和复杂生物膜结构之间的耦合仍然知之甚少。在这里，我们报告了在层流条件下悬浮在弯曲微通道的中间平面中的生物膜飘带的形成。使用不同突变株的实验使我们能够确定细胞外基质的积累与这些结构的发育之间的联系。对弯曲通道中流动的数值模拟强调了拐角附近存在二次涡旋运动，这表明了导致流光形成的潜在流体动力学机制。我们的研究结果应该与所有可能存在生物膜的液体输送系统的设计相关，并为自然和工业环境中微生物流的起源提供新的见解。
Bacterial biofilms have an enormous impact on medicine, industry and ecology. These microbial communities are generally considered to adhere to surfaces or interfaces. Nevertheless, suspended filamentous biofilms, or streamers, are frequently observed in natural ecosystems where they play crucial roles by enhancing transport of nutrients and retention of suspended particles. Recent studies in streamside flumes and laboratory flow cells have hypothesized a link with a turbulent flow environment. However, the coupling between the hydrodynamics and complex biofilm structures remains poorly understood. Here, we report the formation of biofilm streamers suspended in the middle plane of curved microchannels under conditions of laminar flow. Experiments with different mutant strains allow us to identify a link between the accumulation of extracellular matrix and the development of these structures. Numerical simulations of the flow in curved channels highlight the presence of a secondary vortical motion in the proximity of the corners, which suggests an underlying hydrodynamic mechanism responsible for the formation of the streamers. Our findings should be relevant to the design of all liquid-carrying systems where biofilms are potentially present and provide new insights on the origins of microbial streamers in natural and industrial environments.