Trade-offs in phenotypic noise synchronize emergent topology to actively enhance transport in microbial environments

TL;DR

This study investigates how phenotypic noise in microbial colonies influences their structural transitions and transport properties, revealing a trade-off that self-regulates colony behavior and enhances environmental transport.

Contribution

It uncovers the role of phenotypic noise in synchronizing colony topology and transport, supported by a hydrodynamic model and experimental data.

Findings

Noise in cell geometry correlates with colony transition points.

Trade-off between cell geometry noise and growth rate regulates colony transition.

Emergent hydrodynamic fields enhance transport in microbial colonies.

Abstract

Phenotypic noise underpins homeostasis and fitness of individual cells. Yet, the extent to which noise shapes cell-to-population properties in microbial active matter remains poorly understood. By quantifying variability in confluent \textit{E.coli} strains, we catalogue noise across different phenotypic traits. The noise, measured over different temperatures serving as proxy for cellular activity, spanned more than two orders of magnitude. The maximum noise was associated with the cell geometry and the critical colony area at the onset of mono-to-multilayer transition (MTMT), while the lower bound was set by the critical time of the MTMT. Our results, supported by a hydrodynamic model, suggest that a trade-off between the noise in the cell geometry and the growth rate can lead to the self-regulation of the MTMT timing. The MTMT cascades synchronous emergence of hydrodynamic fields, actively enhancing the micro-environmental transport. Our results highlight how interplay of phenotypic noise triggers emergent deterministic properties, and reveal the role of multifield topology--of the colony structure and hydrodynamics--to insulate confluent systems from the inherent noise associated with natural cell-environment settings.