Surface Chemistry Guides the Orientations of Adhering E. coli Cells Captured from Flow
Surface Chemistry Guides the Orientations of Adhering E. coli Cells Captured from Flow
复制标题
表面化学指导从流中捕获的粘附大肠杆菌细胞的方向
DOI：
10.1021/acs.langmuir.1c00764
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发表时间：
2021
期刊：
影响因子：
3.9
通讯作者：
Santore, Maria M.
中科院分区：
文献类型：
--
作者：
Xu, Zhou;Niu, Wuqi Amy;Rivera, Sylvia L.;Tuominen, Mark T.;Siegrist, M. Sloan;Santore, Maria M.
基于对生物膜-基质界面上细胞取向的观察，以及细胞取向和粘附在生物膜进化和功能中发挥重要作用的报道，我们研究了表面化学对大肠杆菌细胞在流动中捕获的阳离子、疏水或阴离子表面取向的影响。我们描述了从相对于表面和流动方向的温和剪切中捕获的非运动细胞的初始方向。在阳离子表面上观察到的捕获细胞取向的广泛分布表明，当细胞在近表面剪切流中旋转时，细胞对相反电荷表面的快速静电吸引保留了细胞的瞬时取向。而在疏水表面和阴离子表面上，细胞在表面平面和流动方向上的取向比在阳离子表面上的取向稍微多一些。这表明在疏水和阴离子表面的粘附发展较慢，允许细胞在粘附时向表面倾斜。一旦细胞被捕获，流量增加了20倍。细胞并没有在阳离子表面重新定向，这表明细胞表面有很强的结合。相比之下，在疏水和阴离子表面，增加的剪切迫使细胞向表面倾斜，并在流动方向上对齐，这一过程在减少剪切后是可逆的。这些发现提示了表面化学可能在微生物群落结构和功能进化中发挥作用的机制。
Motivated by observations of cell orientation at biofilm–substrate interfaces and reports that cell orientation and adhesion play important roles in biofilm evolution and function, we investigated the influence of surface chemistry on the orientation ofEscherichia colicells captured from flow onto surfaces that were cationic, hydrophobic, or anionic. We characterized the initial orientations of nonmotile cells captured from gentle shear relative to the surface and flow directions. The broad distribution of captured cell orientations observed on cationic surfaces suggests that rapid electrostatic attractions of cells to oppositely charged surfaces preserve the instantaneous orientations of cells as they rotate in the near-surface shearing flow. By contrast, on hydrophobic and anionic surfaces, cells were oriented slightly more in the plane of the surface and in the flow direction compared with that on the cationic surface. This suggests slower development of adhesion at hydrophobic and anionic surfaces, allowing cells to tip toward the surface as they adhere. Once cells were captured, the flow was increased by 20-fold. Cells did not reorient substantially on the cationic surface, suggesting a strong cell–surface bonding. By contrast, on hydrophobic and anionic surfaces, increased shear forced cells to tip toward the surface and align in the flow direction, a process that was reversible upon reducing the shear. These findings suggest mechanisms by which surface chemistry may play a role in the evolving structure and function of microbial communities.