Gaboriaud Fabien, Bailet Sidney, Dague Etienne, Jorand Frédéric
Laboratoire de Chimie Physique et Microbiologie pour l'Environnement, UMR 7564, CNRS, Université Henri Poincaré, Nancy 1, 405 rue de Vandoeuvre, F-54600, Villers-lès-Nancy, France.
J Bacteriol. 2005 Jun;187(11):3864-8. doi: 10.1128/JB.187.11.3864-3868.2005.
The nanomechanical properties of gram-negative bacteria (Shewanella putrefaciens) were investigated in situ in aqueous solutions at two pH values, specifically, 4 and 10, by atomic force microscopy (AFM). For both pH values, the approach force curves exhibited subsequent nonlinear and linear regimens that were related to the progressive indentation of the AFM tip in the bacterial cell wall, including a priori polymeric fringe (nonlinear part), while the linear part was ascribed to compression of the plasma membrane. These results indicate the dynamic of surface ultrastructure in response to changes in pH, leading to variations in nanomechanical properties, such as the Young's modulus and the bacterial spring constant.
通过原子力显微镜（AFM）在两种pH值（具体为4和10）的水溶液中对革兰氏阴性菌（腐败希瓦氏菌）的纳米力学特性进行了原位研究。对于这两种pH值，接近力曲线均呈现出随后的非线性和线性阶段，这与AFM针尖在细菌细胞壁中的渐进压痕有关，包括先验的聚合物边缘（非线性部分），而线性部分归因于质膜的压缩。这些结果表明了表面超微结构响应pH变化的动态过程，导致纳米力学特性发生变化，如杨氏模量和细菌弹簧常数。
