论文标题
细菌菌落的缺陷动力学
Defect dynamics in growing bacterial colonies
论文作者
论文摘要
棒状细菌的菌落构成具有氮特性的胶体活性物质系统。作为单个初始细菌通过重复分裂乘以乘积，所产生的菌落迅速失去了远距离定向顺序，但保留了本地有序的域。在这些领域的边界上，拓扑缺陷出现，随着菌落的增长，它们随机移动。在实验和模拟中，我们发现这些缺陷都是以与菌落的指数生长相对应的速率产生的，从而导致稳定的缺陷密度。这种缺陷密度和菌落的相关长度都受杆状颗粒的长宽比调节。此外，我们发现缺陷动力学通过伽马分布很好地描述，这是由于细菌的重复分裂和随后的重新定位所致。
Colonies of rod-shaped bacteria constitute a system of colloidal active matter with nematic properties. As a single initial bacterium multiplies through repeated divisions, the resulting colony quickly loses long-range orientational order, but retains locally ordered domains. At the boundaries of these domains, topological defects emerge, which move around randomly as the colony grows. In both experiments and simulations, we find that these defects are created at a rate that corresponds to the exponential growth of the colony, resulting in a stable defect density. Both this defect density and the colony's correlation length are regulated by the aspect ratio of the rod-shaped particles. Moreover, we find that the defect dynamics are well described by a Gamma distribution, which is due to repeated divisions and subsequent re-orientations of the bacteria.
