How bacteria navigate through complex environments*

Understanding the fundamental principles governing bacterial motility and navigation is crucial for comprehending critical phenomena, such as infectious disease transmission and biofilm formation. For swimming bacteria, efficient navigation through complex environments, such as structured soil, poses a significant challenge. In this presentation, I will delve into the intricate correlation between the microscale navigation of bacteria and their large-scale movement in diverse and heterogeneous environments.

Our study involves a combination of experimental analysis using the soil bacterium Pseudomonas putida and active particle modeling. Specifically, we examine how the disordered environment (agar) guides the migration patterns of these bacteria, leading to remarkable motility characteristics. In contrast to E. coli, our research reveals the transient subdiffusion of bacteria in agar, primarily due to intermittent trapping. These findings highlight a dynamic hop-and-trap mechanism, with trap times following a power-law distribution. I will discuss the implications of these discoveries and their influence on our understanding of bacterial chemotaxis in complex environments.