Microdomains and Stress Distributions in Bacterial Monolayers on Curved Interfaces

Abstract

Monolayers of growing non-motile rod-shaped bacteria act as active nematic materials composed of hard particles rather than the flexible components of other commonly studied active nematics. The organization of these granular monolayers has been studied on flat surfaces but not on curved surfaces, which are known to change the behavior of other active nematics. We use molecular dynamics simulations to track alignment and stress in growing monolayers fixed to curved surfaces, and investigate how these vary with changing surface curvature and cell aspect ratio. We find that the length scale of alignment (measured by average microdomain size) increases with cell aspect ratio and decreases with curvature. Additionally, we find that alignment controls the distribution of extensile stresses in the monolayer by concentrating stress in low-order regions. These results connect active nematic physics to bacterial monolayers and can be applied to model bacteria growing on droplets, such as marine oil-degrading bacteria.

References in corpus (6)

• Topology and Dynamics of Active Nematic Vesicles
• Theory of defect-mediated morphogenesis
• Active nematic defects and epithelial morphogenesis
• Fingering Instability of Active Nematic Droplets
• Active nematodynamics on curved surfaces -- the influence of geometric forces on motion patterns of topological defects
• Tubulation and dispersion of oil by bacterial growth on droplets

Cited by in corpus (6)

• Microbes in porous environments: From active interactions to emergent feedback
• Collective mechano-response dynamically tunes cell-size distributions in growing bacterial colonies
• Colloidal smectics in button-like confinements: experiment and theory
• Strain rate controls alignment in growing bacterial monolayers
• Stress and Alignment Response to Curved Obstacles in Growing Bacterial Monolayers
• Sensitive particle shape dependence of growth-induced mesoscale nematic structure