Tao Antai, Liu Guangzhe, Zhang Rongjing, Yuan Junhua
Hefei National Research Center for Physical Sciences at the Microscale and Department of Physics, University of Science and Technology of China, Hefei, Anhui, 230026, P. R. China.
Wenzhou Institute, University of Chinese Academy of Science, Wenzhou, Zhejiang, 325000, P. R. China.
Adv Sci (Weinh). 2025 Sep;12(34):e02063. doi: 10.1002/advs.202502063. Epub 2025 Jun 20.
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, how bacteria strategically navigate these factors is revealed. It is observed 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, it is found 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 2D environment most efficiently to find potential livable sites.
在自然环境中，固体表面对细菌而言既带来机遇，也构成挑战。一方面，它们为生物膜形成提供平台，这对细菌在恶劣条件下的定殖和恢复力至关重要。另一方面，表面会长时间困住细菌，并迫使它们沿圆形轨迹游动，与它们在大量液体中所享有的自由相比，限制了它们对环境的探索。在此，通过系统的单细胞行为测量、现象学建模和理论分析，揭示了细菌如何策略性地应对这些因素。观察到细菌表面停留时间随着翻转偏向从零增加而急剧下降，在野生型大肠杆菌的平均翻转偏向（约0.25）时转变为平稳状态。此外，发现细菌表面扩散率在该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主要由基因表达中的噪声诱导，这反映了细菌后代持久性的一种策略：在没有刺激线索的情况下，一些细菌会迅速逃离附近缺乏营养的表面，而其他表面停留时间较长的细菌则最有效地探索这个二维环境以找到潜在的宜居位点。
