A thin-film extensional flow model for biofilm expansion by sliding motility
A thin-film extensional flow model for biofilm expansion by sliding motility
复制标题
通过滑动运动实现生物膜扩张的薄膜拉伸流动模型
DOI：
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发表时间：
2019
期刊：
影响因子：
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通讯作者：
B. Binder
中科院分区：
文献类型：
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作者：
Alexander K. Y. Tam;J. Green;Sanjeeva Balasuriya;Ee Lin Tek;J. Gardner;Joanna F. Sundstrom;V. Jiranek;B. Binder
在糖蛋白的存在下，细菌和酵母菌生物膜被假设为通过滑动运动来扩展。这涉及一片细胞作为一个单位扩散，由细胞增殖和对基质的弱粘附促进。在本文中，我们推导出一个拉伸流动模型的生物膜扩张的滑动运动来检验这一假设。我们将生物膜模拟为两相（活细胞和细胞外基质）粘性流体混合物，并模拟从基质中的营养消耗和吸收。应用薄膜近似简化了模型，并将其降为一维轴对称形式。与酿酒酵母垫形成实验的比较表明，实验膨胀速度和O（1）参数估计从实验模型的数值解之间有很好的协议。这证实了滑动运动是酵母生物膜扩张的可能机制。建立了模型的生物相关性，然后我们演示了模型参数如何影响扩张速度，使我们能够预测不同实验条件下的生物膜扩张。最后，我们表明，我们的模型可以解释在一些生物膜中观察到的脊的形成。如果表面张力较低（正如滑动运动性所假设的那样），则尤其如此。
In the presence of glycoproteins, bacterial and yeast biofilms are hypothesized to expand by sliding motility. This involves a sheet of cells spreading as a unit, facilitated by cell proliferation and weak adhesion to the substratum. In this paper, we derive an extensional flow model for biofilm expansion by sliding motility to test this hypothesis. We model the biofilm as a two-phase (living cells and an extracellular matrix) viscous fluid mixture, and model nutrient depletion and uptake from the substratum. Applying the thin-film approximation simplifies the model, and reduces it to one-dimensional axisymmetric form. Comparison with Saccharomyces cerevisiae mat formation experiments reveals good agreement between experimental expansion speed and numerical solutions to the model with O(1) parameters estimated from experiments. This confirms that sliding motility is a possible mechanism for yeast biofilm expansion. Having established the biological relevance of the model, we then demonstrate how the model parameters affect expansion speed, enabling us to predict biofilm expansion for different experimental conditions. Finally, we show that our model can explain the ridge formation observed in some biofilms. This is especially true if surface tension is low, as hypothesized for sliding motility.