Optimal search in E.coli chemotaxis

Abstract

We study chemotaxis of a single {\sl E.coli} bacterium in a medium where the nutrient chemical is also undergoing diffusion and its concentration has the form of a Gaussian whose width increases with time. We measure the average first passage time of the bacterium at a region of high nutrient concentration. In the limit of very slow nutrient diffusion, the bacterium effectively experiences a Gaussian concentration profile with a fixed width. In this case we find that there exists an optimum width of the Gaussian when the average first passage time is minimum, {\sl i.e.}, the search process is most efficient. We verify the existence of the optimum width for the deterministic initial position of the bacterium and also for the stochastic initial position, drawn from uniform and steady state distributions. Our numerical simulation in a model of a non-Markovian random walker agrees well with our analytical calculations in a related coarse-grained model. We also present our simulation results for the case when the nutrient diffusion and bacterial motion occur over comparable time-scales and the bacterium senses a time-varying concentration field.

References in corpus (9)

• Diffusion with Stochastic Resetting
• Intermittent search strategies
• Diffusion with Optimal Resetting
• First order transition for the optimal search time of Lévy flights with resetting
• Optimal diffusive search: nonequilibrium resetting versus equilibrium dynamics
• Classes of fast and specific search mechanisms for proteins on DNA
• First-passage time of run-and-tumble particles
• The Bacterial Chemotactic Response Reflects a Compromise Between Transient and Steady State Behavior
• Chemotaxis When Bacteria Remember: Drift versus Diffusion

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• Short time extremal response to step stimulus for a single cell {\sl E. coli}
• Analytical Approach for Calculating Chemotaxis Sensitivity Function