Bacterial Route Finding and Collective Escape in Mazes and Fractals

Trung V Phan,Julia Bos,Tuan K Do,Ryan Morris,James C Sturm,Robert H Austin,Ke-Chih Lin,Krisztina Nagy,Matthew E Black

doi:10.1103/physrevx.10.031017

Abstract

Experiments show that E. coli bacteria employ a number of strategies to explore complex environments, navigating mazes and fractals much more efficiently than would be expected for a random walk.

Highlights

The two topologies of mazes and fractals pose quite different challenges to motile bacteria
Motile bacteria are sensitive to net biases in flow, called rheotaxis [12], and may be unable to swim against too strong a flow velocity
As we show, depending on the sign of the flow into or out of the maze entrance, the collective bacteria population escape dynamics are quite different, which we attribute here to changes in the bacterial population dynamics rather than rheotaxis

Summary

Introduction

The two topologies of mazes and fractals pose quite different challenges to motile bacteria. A maze typically has well-defined entrance and exit ports [1]. The key characteristic of a fractal is self-similarity: A fractal looks locally the same as you branch down into the fractal, there are no obvious physical clues as to how deep you are into the fractal, and this makes escape from a fractal more challenging from a maze. We show that chemotactic bacteria get temporarily trapped in a fractal but eventually escape in a collective manner

Methods

Results

Conclusion