Front-propagation in bacterial inter-colony communication

TL;DR

This paper investigates how bacterial colonies communicate through signaling molecules, revealing that the concentration spreads exponentially with uniform speed, supported by theoretical models and experimental validation with Sinorhizobium meliloti.

Contribution

It introduces a theoretical model describing exponential spreading of signaling molecules in bacterial colonies and validates it with experimental data.

Findings

Signaling molecule concentration spreads exponentially with uniform speed.

Experimental results with Sinorhizobium meliloti support the theoretical model.

Inter-colony communication dynamics are characterized by exponential concentration profiles.

Abstract

Many bacterial species exchange signaling molecules to coordinate population-wide responses. For this process known as quorum sensing the concentration of the respective molecules is crucial. Here we consider the interaction between spatially distributed bacterial colonies so that the spreading of the signaling molecules in space becomes important. The exponential growth of the signal-producing populations and the corresponding increase in signaling molecule production result in an exponential concentration profile that spreads with uniform speed. The theoretical predictions are supported by experiments with different strains of the soil bacterium Sinorhizobium meliloti that display fluorescence when either producing or responding to the signaling molecules.