Self-similar dynamics of bacterial chemotaxis

TL;DR

This paper investigates the self-similar pattern formation in bacterial colonies driven by chemotaxis, revealing explicit scaling laws and the evolution of colonies as traveling waves with sharp fronts.

Contribution

It introduces a continuum model that describes the self-similar dynamics of bacterial colonies influenced by chemotaxis, providing new insights into their growth patterns.

Findings

Bacterial colonies exhibit self-similar patterns under uniform chemical gradients.

The explicit scaling law of colony growth is derived.

Colonies evolve as traveling waves with sharp fronts over time.

Abstract

Colonies of bacteria grown on thin agar plate exhibit fractal patterns as a result of adaptation to their environments. The bacterial colony pattern formation is regulated crucially by chemotaxis, the movement of cells along a chemical concentration gradient. Here, the dynamics of pattern formation in bacterial colony is investigated theoretically through a continuum model that considers chemotaxis. In the case of the gradient sensed by the bacterium is nearly uniform, the bacterial colony patterns are self-similar, which they look the same at every scale. The scaling law of the bacterial colony growth has been revealed explicitly. Chemotaxis biases the movement of bacterial population in colony trend toward the chemical attractant. Moreover, the bacterial colonies evolve long time as the traveling wave with sharp front.