标题： 细菌优化停顿偏向以战略性地穿越表面约束 显示英文标题

标题： Bacteria optimize tumble bias to strategically navigate surface constraints

摘要： 在自然环境中，固体表面为细菌提供了机会和挑战。 一方面，它们作为生物膜形成的平台，对于细菌的定植和在恶劣条件下的耐受性至关重要。 另一方面，表面可以长时间困住细菌，并迫使它们沿圆形轨迹游动，与在体液中体验到的自由相比，限制了它们对环境的探索。 在这里，通过系统的单细胞行为测量、现象建模和理论分析，我们揭示了细菌如何战略性地应对这些因素。 我们观察到，随着翻转偏向从零增加，细菌的表面停留时间急剧减少，在野生型大肠杆菌（约0.25）的平均翻转偏向处达到平台期。 此外，我们发现细菌的表面扩散率在这一平均翻转偏向附近达到峰值。 考虑到细菌翻转偏向的表型变异，这主要是由基因表达中的噪声引起的，这反映了细菌后代持续存在的策略：在没有刺激线索的情况下，一些细菌迅速逃离附近的表面，以防其缺乏营养，而另一些具有更长表面停留时间的细菌则最有效地探索这个二维环境，以寻找潜在的宜居区域。 显示英文摘要

摘要： In natural environments, solid surfaces present both opportunities and challenges for bacteria. On one hand, they serve as platforms for biofilm formation, crucial for bacterial colonization and resilience in harsh conditions. On the other hand, surfaces can entrap bacteria for extended periods and force them to swim along circular trajectories, constraining their environmental exploration compared to the freedom they experience in the bulk liquid. Here, through systematic single-cell behavioral measurements, phenomenological modeling, and theoretical analysis, we reveal how bacteria strategically navigate these factors. We observe that bacterial surface residence time decreases sharply with increasing tumble bias from zero, transitioning to a plateau at the mean tumble bias of wild-type Escherichia coli (~ 0.25). Furthermore, we find that bacterial surface diffusivity peaks near this mean tumble bias. Considering the phenotypic variation in bacterial tumble bias, which is primarily induced by noise in gene expression, this reflects a strategy for bacterial offspring persistence: In the absence of stimulus cues, some bacteria swiftly escape from the nearby surface in case it lacks nutrients, while others, with longer surface residence times, explore this two-dimensional environment most efficiently to find potential livable sites.