细菌定植早期表面扩散减慢
Slowdown of the surface diffusion during early stages of bacterial colonization
摘要：
我们研究的表面扩散的模式蓝藻集胞藻属PCC $6803$在初期阶段的细胞接触的玻璃表面在稀制度。我们观察到一个抽搐运动与交替不动的“翻滚”和移动的“运行”期间，导致在一个正常的扩散所描述的连续时间随机游走扩散系数$D$。令人惊讶的是，发现$D$随时间降低至平台。只有当蓝藻细胞能够产生释放的胞外多糖时，才能观察到这一点，如野生型菌株和各种多糖耗尽突变体之间的比较研究所示。的细菌细胞所采取的轨迹的分析表明，其间歇性运动的时间特性取决于在扩散过程中访问的网站的瞬时分数。这定量描述了与多糖的渐进表面覆盖相关的$D$的时间依赖性。所观察到的表面扩散的减缓可能构成了微菌落形成的基本前体机制，并为控制生物膜形成提供了线索。
英文摘要：
We study the surface diffusion of the model cyanobacterium Synechocystis sp. PCC $6803$ during the incipient stages of cell contact with a glass surface in the dilute regime. We observe a twitching motility with alternating immobile "tumble" and mobile "run" periods, resulting in a normal diffusion described by a continuous time random walk with a coefficient of diffusion $D$. Surprisingly, $D$ is found to decrease with time down to a plateau. This is observed only when the cyanobacterial cells are able to produce released extracellular polysaccharides, as shown by a comparative study between the wild-type strain and various polysaccharides-depleted mutants. The analysis of the trajectories taken by the bacterial cells shows that the temporal characteristics of their intermittent motion depend on the instantaneous fraction of visited sites during diffusion. This describes quantitatively the time dependence of $D$, related to the progressive surface coverage by the polysaccharides. The observed slowdown of the surface diffusion may constitute a basic precursor mechanism for microcolony formation and provides clues for controlling biofilm formation.
机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。
