School of Mechanical Engineering, University of Science and Technology Beijing, 30 Xueyuan Road, Haidian District, Beijing, 100083, China.
School of Engineering and Applied Sciences, Harvard University, Cambridge, MA, 02138, USA.
Arch Microbiol. 2021 Nov;203(9):5635-5645. doi: 10.1007/s00203-021-02542-w. Epub 2021 Aug 31.
Self-healing is an intrinsic ability that exists widely in every multicellular biological organism. Our recent experiments have shown that bacterial biofilms also have the ability to self-heal after man-make cuts, but the mechanism of biofilm self-healing have not been studied. We find that the healing process of cuts on the biofilm depends on cut geometries like its location or direction, the biofilm itself like the biofilm age, the growing substrate properties like its hardness, and also the environments such as the competitive growth of multiple biofilms. What is more, the healing rate along the cut is heterogeneous, and the maximum healing rate can reach 260 μm/h, which is three times the undestroyed biofilm expansion rate. The cut does not change the rounded shape growth of biofilms. Further study of phenotypic evolution shows that the cut delays bacterial differentiation; motile cells perceive the cut and move to the cut area, while the cut only heals when there are enough matrix-producing cells in the cut area. Our work suggests new ideas for developing self-healing materials.
自愈合是一种普遍存在于多细胞生物中的内在能力。我们最近的实验表明，细菌生物膜在人为切割后也具有自愈合的能力，但生物膜自愈合的机制尚未得到研究。我们发现，生物膜切割的愈合过程取决于切割的几何形状，如切割的位置或方向，生物膜本身，如生物膜的年龄，以及生长基质的特性，如硬度，还取决于环境，如多个生物膜的竞争生长。更重要的是，沿着切割的愈合速度是不均匀的，最大愈合速度可以达到 260 μm/h，是未破坏生物膜扩展速度的三倍。切割不会改变生物膜的圆形生长形状。对表型进化的进一步研究表明，切割会延迟细菌的分化；运动细胞感知到切割并移动到切割区域，只有当切割区域中有足够的产生基质的细胞时，切割才会愈合。我们的工作为开发自愈合材料提供了新的思路。
