Department of Civil and Environmental Engineering, University of Alberta, Edmonton, Alberta, T6G 2W2, Canada.
Biofouling. 2012;28(6):525-38. doi: 10.1080/08927014.2012.694138.
Extracellular polymeric substances (EPS) significantly influence bacterial adhesion to solid surfaces, but it is difficult to elucidate the role of EPS on bacterial adhesion due to their complexity and variability. In the present study, the effect of EPS on the initial adhesion of B. cepaciaepacia PC184 and P. aeruginosa PAO1 on glass slides with and without an EPS precoating was investigated under three ionic strength conditions. The surface roughness of EPS coated slides was evaluated by atomic force microscopy (AFM), and its effect on initial bacterial adhesion was found to be trivial. X-ray photoelectron spectroscopy (XPS) studies were performed to determine the elemental surface compositions of bacterial cells and substrata. The results showed that an EPS precoating hindered bacterial adhesion on solid surfaces, which was largely attributed to the presence of proteins in the EPS. This observation can be attributed to the increased steric repulsion at high ionic strength conditions. A steric model for polymer brushes that considers the combined influence of steric effects and DLVO interaction forces is shown to adequately describe bacterial adhesion behaviors.
细胞外聚合物（EPS）对细菌在固体表面的附着有重要影响，但由于其复杂性和可变性，很难阐明 EPS 在细菌附着中的作用。本研究在三种离子强度条件下，考察了 EPS 对无预涂 EPS 和有 EPS 预涂玻片上 B. cepaciaepacia PC184 和 P. aeruginosa PAO1 初始附着的影响。原子力显微镜（AFM）评估了涂有 EPS 的玻片的表面粗糙度，发现其对初始细菌附着的影响微不足道。X 射线光电子能谱（XPS）研究用于确定细菌细胞和基底的表面元素组成。结果表明，EPS 预涂层阻碍了细菌在固体表面的附着，这主要归因于 EPS 中存在蛋白质。这一观察结果可以归因于在高离子强度条件下增加的空间排斥。一个考虑到空间效应和 DLVO 相互作用力综合影响的聚合物刷的空间模型被证明可以充分描述细菌附着行为。
