Stripe formation in bacterial systems with density-suppressed motility

TL;DR

This paper investigates how bacteria with density-dependent motility form periodic stripe patterns on agar plates through a kinetic model that includes growth and motility suppression.

Contribution

It introduces a theoretical kinetic model explaining stripe formation in bacteria with density-suppressed motility, including an analytic method to determine phase boundaries.

Findings

Identified conditions for stripe formation versus no-stripe phases.

Derived an analytic ansatz for the phase boundary.

Analyzed the influence of parameters on pattern formation.

Abstract

Engineered bacteria in which motility is reduced by local cell density generate periodic stripes of high and low density when spotted on agar plates. We study theoretically the origin and mechanism of this process in a kinetic model that includes growth and density-suppressed motility of the cells. The spreading of a region of immotile cells into an initially cell-free region is analyzed. From the calculated front profile we provide an analytic ansatz to determine the phase boundary between the stripe and the no-stripe phases. The influence of various parameters on the phase boundary is discussed.