Arnoldi M, Fritz M, Bäuerlein E, Radmacher M, Sackmann E, Boulbitch A
Physik Department, Institut für Biophysik, E22, Technische Universität München, James-Franck-Strasse, 85747 Garching bei München, Germany.
Phys Rev E Stat Phys Plasmas Fluids Relat Interdiscip Topics. 2000 Jul;62(1 Pt B):1034-44. doi: 10.1103/physreve.62.1034.
We report a study of the deformability of a bacterial wall with an atomic force microscope (AFM). A theoretical expression is derived for the force exerted by the wall on the cantilever as a function of the depths of indentation generated by the AFM tip. Evidence is provided that this reaction force is a measure for the turgor pressure of the bacterium. The method was applied to magnetotactic bacteria of the species Magnetospirillum gryphiswaldense. Force curves were generated on the substrate and on the bacteria while scanning laterally. With the mechanical properties so gained we obtained the spring constant of the bacterium as a whole. Making use of our theoretical results we determined the turgor pressure to be in the range of 85 to 150 kPa.
我们报告了一项使用原子力显微镜（AFM）对细菌细胞壁可变形性的研究。推导了细胞壁对悬臂施加的力作为AFM针尖产生的压痕深度函数的理论表达式。提供的证据表明，这种反作用力是细菌膨压的一种度量。该方法应用于格氏嗜盐碱杆菌属的趋磁细菌。在横向扫描时，在底物和细菌上生成力曲线。利用由此获得的力学性能，我们得到了整个细菌的弹簧常数。利用我们的理论结果，我们确定膨压在85至150 kPa范围内。
