Effects of biofilm heterogeneity on the apparent mechanical properties obtained by shear rheometry.
Effects of biofilm heterogeneity on the apparent mechanical properties obtained by shear rheometry.
复制标题
生物膜异质性对剪切流变测定获得的表观机械性能的影响。
DOI：
10.1002/bit.28276
复制
发表时间：
2023
影响因子：
3.8
通讯作者：
Nerenberg,Robert
中科院分区：
文献类型：
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作者：
Li,Mengfei;Nahum,Yanina;Matouš,Karel;Stoodley,Paul;Nerenberg,Robert
流变仪是一种广泛用于测定生物膜力学性能的实验技术。然而，它表征了整个生物膜的整体力学行为。生物膜机械异质性对流变测量的影响尚不清楚。我们使用实验室实验和计算机建模，以探讨生物膜的机械异质性的流变仪所获得的结果的影响。研究了具有层状力学性质的人工合成生物膜，采用粘弹性生物膜理论，采用Kelvin-Voigt模型。用不同浓度的琼脂凝胶制备层状、异质生物膜，用流变仪在剪切模式下表征其机械性能。实验和模拟都表明，从流变学的生物膜的性质强烈偏置的生物膜的最弱的部分。从以前的研究中使用线性分层的机械性能的模拟结果也表明，较弱的部分的生物膜占主导地位的蠕变试验中的机械性能。我们注意到，该模型可以作为一种预测工具，以探索复杂的生物膜结构的机械行为超出了那些可访问的实验。由于大多数生物膜显示一定程度的机械异质性，我们的研究结果表明，应谨慎使用流变数据的解释。如果机械性质是分层的，则其不一定提供整个生物膜的“平均”机械性质。
Rheometry is an experimental technique widely used to determine the mechanical properties of biofilms. However, it characterizes the bulk mechanical behavior of the whole biofilm. The effects of biofilm mechanical heterogeneity on rheometry measurements are not known. We used laboratory experiments and computer modeling to explore the effects of biofilm mechanical heterogeneity on the results obtained by rheometry. A synthetic biofilm with layered mechanical properties was studied, and a viscoelastic biofilm theory was employed using the Kelvin–Voigt model. Agar gels with different concentrations were used to prepare the layered, heterogeneous biofilm, which was characterized for mechanical properties in shear mode with a rheometer. Both experiments and simulations indicated that the biofilm properties from rheometry were strongly biased by the weakest portion of the biofilm. The simulation results using linearly stratified mechanical properties from a previous study also showed that the weaker portions of the biofilm dominated the mechanical properties in creep tests. We note that the model can be used as a predictive tool to explore the mechanical behavior of complex biofilm structures beyond those accessible to experiments. Since most biofilms display some degree of mechanical heterogeneity, our results suggest caution should be used in the interpretation of rheometry data. It does not necessarily provide the “average” mechanical properties of the entire biofilm if the mechanical properties are stratified.