Bacillus subtilis Bacteria Generate an Internal Mechanical Force within a Biofilm
Bacillus subtilis Bacteria Generate an Internal Mechanical Force within a Biofilm
复制标题
DOI：
10.1016/j.bpj.2015.10.004
复制
发表时间：
2015-11-17
影响因子：
3.4
通讯作者：
Raspaud, Eric
中科院分区：
文献类型：
--
作者：
Douarche, Carine;Allain, Jean-Marc;Raspaud, Eric
理解为什么生物膜是细菌生命的最普遍模式的一个关键问题是细菌从自组织成生物膜群落中获得的抗性和保护程度的起源。我们的实验表明，它们的机械性能是一个关键因素。对枯草芽孢杆菌的表膜或漂浮生物膜的实验表明，当它们繁殖并分泌细胞外物质时，细菌在生物膜内产生内力（与80 +/- 25 Pa应力相关），类似于自我平衡和加强植物，器官和一些工程建筑的力。在这里，我们发现这种力或压力与生长诱导的压力有关。我们的观察结果表明，由于这种力，生物膜在任何切割或消融后扩散高达其初始尺寸的15-20%。力在非常短的时间尺度（几十毫秒）内松弛。我们的结论是，这种力有助于细菌塑造生物膜，提高其机械阻力，并促进其入侵和自我修复。
A key issue in understanding why biofilms are the most prevalent mode of bacterial life is the origin of the degree of resistance and protection that bacteria gain from self-organizing into biofilm communities. Our experiments suggest that their mechanical properties are a key factor. Experiments on pellicles, or floating biofilms, of Bacillus subtilis showed that while they are multiplying and secreting extracellular substances, bacteria create an internal force (associated with a 80 +/- 25 Pa stress) within the biofilms, similar to the forces that self-equilibrate and strengthen plants, organs, and some engineered buildings. Here, we found that this force, or stress, is associated with growth-induced pressure. Our observations indicate that due to such forces, biofilms spread after any cut or ablation by up to 15-20% of their initial size. The force relaxes over very short timescales (tens of milliseconds). We conclude that this force helps bacteria to shape the biofilm, improve its mechanical resistance, and facilitate its invasion and self-repair.