Simultaneous determination of the mechanical properties and turgor of a single bacterial cell using atomic force microscopy
Simultaneous determination of the mechanical properties and turgor of a single bacterial cell using atomic force microscopy
复制标题
使用原子力显微镜同时测定单个细菌细胞的机械特性和膨胀度
作者：
Han R
细菌的力学特性（细胞壁刚度和膨胀）是细菌在恶劣环境中生存的重要因素。对于单个细菌细胞，同时确定细胞壁刚度和膨胀是具有挑战性的。在这项研究中，我们采用有限元建模和数学建模相结合的方法，基于原子力显微镜（AFM）纳米压痕同时确定单个细菌细胞的细胞壁刚度和膨胀。本方法测定的表皮葡萄球菌的力学性能和膨胀度与其他独立研究结果一致。对于给定的水环境，细菌细胞壁的刚度随着膨胀的增加而线性增加。较高的渗透压导致细胞壁刚度和膨胀度的降低。我们还证明了膨胀的变化与细菌细胞粘度的变化有关。
Bacterial mechanical properties (cell wall stiffness and turgor) are important factors for bacterial survival in harsh environments. For an individual bacterial cell, it is challenging to determine the cell wall stiffness and turgor simultaneously. In this study, we adopted a combined finite element modelling and mathematical modelling approach to simultaneously determine bacterial cell wall stiffness and turgor of an individual bacterial cell based on atomic force microscopy (AFM) nanoindentation. The mechanical properties and turgor of Staphylococcus epidermidis, determined by our method are consistent with other independent studies. For a given aqueous environment, bacterial cell wall stiffness increased linearly with an increase in turgor. Higher osmolarity leads to a decrease in both cell wall stiffness and turgor. We also demonstrated that the change of turgor is associated with a change in viscosity of the bacterial cell.