Department of Chemical and Biomolecular Engineering, National University of Singapore, 4 Engineering Drive 4, Singapore 117576, Singapore.
J Colloid Interface Sci. 2011 Dec 1;364(1):213-8. doi: 10.1016/j.jcis.2011.08.021. Epub 2011 Aug 16.
Understanding bacterial adhesion to surfaces requires knowledge of the forces that govern bacterial-surface interactions. Biofilm formation on stainless steel 316 (SS316) by three bacterial species was investigated by examining surface force interaction between the cells and metal surface using atomic force microscopy (AFM). Bacterial-metal adhesion force was quantified at different surface delay time from 0 to 60s using AFM tip coated with three different bacterial species: Gram-negative Massilia timonae and Pseudomonas aeruginosa, and Gram-positive Bacillus subtilis. The results revealed that bacterial adhesion forces on SS316 surface by Gram-negative bacteria is higher (8.53±1.40 nN and 7.88±0.94 nN) when compared to Gram-positive bacteria (1.44±0.21 nN). Physicochemical analysis on bacterial surface properties also revealed that M. timonae and P. aeruginosa showed higher hydrophobicity and surface charges than B. subtilis along with the capability of producing extracellular polymeric substances (EPS). The higher hydrophobicity, surface charges, and greater propensity to form EPS by M. timonae and P. aeruginosa led to high adhesive force on the metal surface.
了解细菌对表面的粘附需要了解控制细菌-表面相互作用的力。通过使用原子力显微镜（AFM）检查细胞与金属表面之间的表面力相互作用，研究了三种细菌在不锈钢 316（SS316）上的生物膜形成。使用涂有三种不同细菌的 AFM 尖端（革兰氏阴性的 Massilia timonae 和 Pseudomonas aeruginosa，以及革兰氏阳性的 Bacillus subtilis），在 0 到 60s 的不同表面延迟时间下定量了细菌-金属粘附力。结果表明，与革兰氏阳性细菌（1.44±0.21 nN）相比，革兰氏阴性细菌（8.53±1.40 nN 和 7.88±0.94 nN）在 SS316 表面上的细菌粘附力更高。对细菌表面特性的理化分析还表明，M. timonae 和 P. aeruginosa 比 B. subtilis 具有更高的疏水性和表面电荷，并且能够产生细胞外聚合物物质（EPS）。M. timonae 和 P. aeruginosa 较高的疏水性、表面电荷和形成 EPS 的更大倾向导致其在金属表面上具有较高的粘附力。
