Travelling waves of invasion in microbial communities with phenotypic switching

TL;DR

This study investigates how phenotypic switching in microbial populations influences invasion dynamics and wave propagation speeds, revealing that persistence can enhance invasion rather than hinder it.

Contribution

It provides a combined analytical and numerical analysis showing phenotypic switching can accelerate invasion waves, challenging traditional views of persistence as solely defensive.

Findings

Phenotypic switching does not affect the invasion speed of the invading species.

Switching can speed up the invasion of the resident population.

Persistence may serve as an offensive ecological strategy.

Abstract

Complex microbial habitats see the spatial competition of different clonal bacterial populations that switch between different phenotypes. Here, we determine the effect of this subpopulation structure on the invasion of one species by another in a minimal model of two competing species: one species switches, both stochastically and in response to its competitor, to a persister phenotype resilient to competition. Surprisingly, our combined analytical and numerical results show that this phenotypic switching has no effect on the speed of the travelling wave by which the competitors invade the first population. Conversely, we discover that phenotypic switching can speed up the wave by which this population invades their competitors. Our results thus suggest, counterintuitively, that bacterial persistence can be an offensive, rather than defensive ecological strategy.