Dynamics of a microorganism moving by chemotaxis in its own secretion

TL;DR

This paper investigates how a microorganism's movement, influenced by its own secreted chemicals, exhibits different behaviors like transient arrest or ballistic motion, depending on whether it attracts or repels itself, through simulations and analysis.

Contribution

It introduces a detailed simulation study of microorganism chemotaxis coupled with its own secretion, revealing new transient behaviors and providing theoretical insights.

Findings

Chemoattractant causes transient dynamical arrest.

Chemorepellent induces transient ballistic motion.

Long-term diffusion occurs in both cases.

Abstract

The Brownian dynamics of a single microorganism coupled by chemotaxis to a diffusing concentration field which is secreted by the microorganism itself is studied by computer simulations in spatial dimensions $d=1,2,3$. Both cases of a chemoattractant and a chemorepellent are discussed. For a chemoattractant, we find a transient dynamical arrest until the microorganism diffuses for long times. For a chemorepellent, there is a transient ballistic motion in all dimensions and a long-time diffusion. These results are interpreted with the help of a theoretical analysis.