Microrheology of growing Escherichia coli biofilms investigated by using magnetic force modulation atomic force microscopy.
Microrheology of growing Escherichia coli biofilms investigated by using magnetic force modulation atomic force microscopy.
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DOI：
10.1116/1.4968809
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发表时间：
2016-12
期刊：
影响因子：
2.1
通讯作者：
Tiansheng Gan;Xiangjun Gong;H. Schönherr;Guangzhao Zhang
中科院分区：
文献类型：
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作者：
Tiansheng Gan;Xiangjun Gong;H. Schönherr;Guangzhao Zhang
生长生物膜的微观流变学提供了关于其结构演变和性质的有洞察力的信息。在这项研究中，作者用磁力调制原子力显微镜研究了不同压痕深度(δ)下的大肠杆菌(Hcb1菌株)生物膜的微观流变学。随着δ的增大，生物膜早期的动态刚度(Ks)显著增大。然而，当生物膜成熟时，它会趋于平稳。事实表明，生物膜的结构由非均质向均质转变。此外，Ks被标度为f，这与软玻璃的流变性相吻合。该指数随培养时间的延长而增大，表明生物膜处于流态化状态。相反，成熟生物膜的上层是类似固体的，其储能模数总是大于损失模数，其粘弹性受剪应力的影响较小。
Microrheology of growing biofilms provides insightful information about its structural evolution and properties. In this study, the authors have investigated the microrheology of Escherichia coli (strain HCB1) biofilms at different indentation depth (δ) by using magnetic force modulation atomic force microscopy as a function of disturbing frequency (f). As δ increases, the dynamic stiffness (ks) for the biofilms in the early stage significantly increases. However, it levels off when the biofilms are matured. The facts indicate that the biofilms change from inhomogeneous to homogeneous in structure. Moreover, ks is scaled to f, which coincides with the rheology of soft glasses. The exponent increases with the incubation time, indicating the fluidization of biofilms. In contrast, the upper layer of the matured biofilms is solidlike in that the storage modulus is always larger than the loss modulus, and its viscoelasticity is slightly influenced by the shear stress.