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.

自愈是一种内在能力，广泛存在于每一个多细胞生物有机体中。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能力，但尚未研究生物膜自愈的机制。我们发现，生物膜上切口的愈合过程取决于切口的几何形状，例如其位置或方向，生物膜本身（例如生物膜年龄），生长的基质特性（例如其硬度）以及环境（例如多个生物膜的竞争性生长）。更重要的是，沿切口的愈合率是不均匀的，最大愈合率可达260 μm/h，是未破坏生物膜膨胀率的3倍。切割不会改变生物膜的圆形生长。对表型进化的进一步研究表明，切割延迟了细菌分化；运动细胞感知切口并移动到切口区域，而切口只有在切口区域有足够的基质产生细胞时才会愈合。我们的工作提出了开发自愈材料的新思路。