Cellular memory enhances bacterial chemotactic navigation in rugged environments

较慢的游动促进细菌与小型浮游植物之间的趋化相遇

Slower swimming promotes chemotactic encounters between bacteria and small phytoplankton

本研究计算了趋化性相较于随机运动对细菌与浮游植物相遇速率提升的上限，揭示了浮游植物大小、细菌游动速度与趋化收益的关联，以及不同营养水域中趋化优势的不对称性，为海洋细菌表型共存提供了解释。

Influence of confinement on the spreading of bacterial populations

The spreading of bacterial populations is central to processes in agriculture, the environment, and medicine. However, existing models of spreading typically focus on cells in unconfined settings--despite the fact that many bacteria inhabit complex and crowded environments, such as soils, sediments, and biological tissues/gels, in which solid obstacles confine the cells and thereby strongly regulate population spreading. Here, we develop an extended version of the classic Keller-Segel model of bacterial spreading that incorporates the influence of confinement in promoting both cell-solid and c…

行波引诱物环境中的细菌趋化性

Bacterial Chemotaxis in a Traveling Wave Attractant Environment

本文通过模拟研究大肠杆菌在行波引诱物环境中的趋化漂移速度，揭示了漂移速度随波速变化出现变号和多个峰值的反直觉行为，并从细胞顺波与逆波运行时感知梯度差异的角度给出了定量解释。

Cellular Sensing Governs the Stability of Chemotactic Fronts

In contexts ranging from embryonic development to bacterial ecology, cell populations migrate chemotactically along self-generated chemical gradients, often forming a propagating front. Here, we theoretically show that the stability of such chemotactic fronts to morphological perturbations is determined by limitations in the ability of individual cells to sense and thereby respond to the chemical gradient. Specifically, cells at bulging parts of a front are exposed to a smaller gradient, which slows them down and promotes stability, but they also respond more strongly to the gradient, which sp…

3D spatial exploration by E. coli echoes motor temporal variability

Unraveling bacterial strategies for spatial exploration is crucial for understanding the complexity in the organization of life. Bacterial motility determines the spatio-temporal structure of microbial communities, controls infection spreading and the microbiota organization in guts or in soils. Most theoretical approaches for modeling bacterial transport rely on their run-and-tumble motion. For Escherichia coli, the run time distribution was reported to follow a Poisson process with a single characteristic time related to the rotational switching of the flagellar motors. However, direct measu…

大肠杆菌通过负趋化性形成图案：不稳定性、凝聚与合并

Pattern formation in e. coli through negative chemotaxis: instability, condensation, and merging

本研究结合实验与修正的Keller-Segel方程模型，探究了大肠杆菌在均匀压力下通过负趋化性形成凝聚物的动力学，揭示了其在不同时间尺度上的不稳定性、凝聚物形成与合并机制，并发现相邻聚集物间的作用力随距离指数衰减。

Genetic noise mechanism for power-law switching in bacterial flagellar motors

Switching of the direction of flagella rotations is the key control mechanism governing the chemotactic activity of E. coli and many other bacteria. Power-law distributions of switching times are most peculiar because their emergence cannot be deduced from simple thermodynamic arguments. Recently it was suggested that by adding finite-time correlations into Gaussian fluctuations regulating the energy height of barrier between the two rotation states, one can generate a power-law switching statistics. By using a simple model of a regulatory pathway, we demonstrate that the required amount of co…

通过无需重置的分层强化学习实现微型机器人趋化性

Enabling microrobotic chemotaxis via reset-free hierarchical reinforcement learning

该研究利用两级分层强化学习，实现了多连杆微型机器人的趋化导航，同时达成无需重置的部分可观测RL，为解决微型机器人强化学习的现实难题提供方案。