Confinement and activity regulate bacterial motion in porous media

Abstract

Understanding how bacteria move in porous media is critical to applications in healthcare, agriculture, environmental remediation, and chemical sensing. Recent work has demonstrated that E. coli, which moves by run-and-tumble dynamics in a homogeneous medium, exhibits a new form of motility when confined in a disordered porous medium: hopping-and-trapping motility, in which cells perform rapid, directed hops punctuated by intervals of slow, undirected trapping. Here, we use direct visualization to shed light on how these processes depend on pore-scale confinement and cellular activity. We find that hopping is determined by pore-scale confinement, and is independent of cellular activity; by contrast, trapping is determined by the competition between pore-scale confinement and cellular activity, as predicted by an entropic trapping model. These results thus help to elucidate the factors that regulate bacterial motion in porous media, and could help aid the development of new models of motility in heterogeneous environments.

References in corpus (6)

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Cited by in corpus (11)

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• Active Brownian and inertial particles in disordered environments: short-time expansion of the mean-square displacement
• Active diffusion of self-propelled particles in flexible polymer networks
• Directional Locking Effects for Active Matter Particles Coupled to a Periodic Substrate
• Active Matter Commensuration and Frustration Effects on Periodic Substrates
• The Influence of Motility on Bacterial Accumulation in a Microporous Channel
• Influence of confinement on the spreading of bacterial populations
• Active Matter Shepherding and Clustering in Inhomogeneous Environments
• Phase separation of self-propelled disks with ferromagnetic and nematic alignment