Faculty of Materials Science and Engineering, South China University of Technology , Guangzhou 510640, P. R. China.
Langmuir. 2017 Apr 11;33(14):3525-3533. doi: 10.1021/acs.langmuir.7b00439. Epub 2017 Mar 28.
Landing of bacteria for adhesion on a surface is a common phenomenon in our life. However, how surface properties are involved in this process remains largely unclear. Using digital holographic microscopy, we investigated the three-dimensional motions of flagellate Escherichia coli swimming near polymeric surfaces with different properties in aqueous solution before adhesion. We monitored the bacteria landing dynamics, which shows that the density distribution, the probability, and the orientation for collisions of the bacteria are determined by their motility but are slightly affected by the surface properties. However, surface hydrophobicity reduces the near-wall velocity of the bacteria through collisions and slightly increases the collision duration. This promotes the landing and adhesion of bacteria. By contrast, most bacteria collide with the surface using their flagella, which resist adhesion.
细菌在表面上的附着是我们生活中常见的现象。然而，表面性质在这个过程中是如何参与的，目前还不是很清楚。我们利用数字全息显微镜，在细菌附着前，研究了在水溶液中，不同性质聚合物表面附近鞭毛型大肠杆菌的三维运动。我们监测了细菌的附着动力学，结果表明，细菌的密度分布、碰撞概率和碰撞方向由它们的运动性决定，但受表面性质的影响很小。然而，表面疏水性通过碰撞降低了细菌的近壁速度，并略微增加了碰撞持续时间，这促进了细菌的附着和黏附。相比之下，大多数细菌通过鞭毛与表面碰撞，从而抵抗黏附。
