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

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 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. Note: The manuscript is supported and accompanied by a Supplementary Information section.

Fluctuation-induced dynamics of nematic topological defects

“…Fluctuations, represented by temperature in classical models, are known to drive many phase transitions, and are of particular importance in biological systems [22][23][24][25]. Noise is known to drive the BKT transition, in which spontaneously generated topological defects break the order, in a 2-dimensional passive, dry nematic, shown analytically by renormalisation group analyses [13] and computationally for a lattice model with finite size scaling [26], and for a dry, freely moving, particle-based model for various length to width ratios [27,28].…”