Selective Trapping of Bacteria in Porous Media by Cell Length

Area of Science:

• Microbiology
• Biophysics
• Environmental Science

Background:

• Bacteria inhabit complex porous environments like soil and host tissues.
• Understanding bacterial navigation in these settings is crucial but challenging.
• The influence of cell shape and pore geometry on bacterial motility is poorly understood.

Purpose of the Study:

• To investigate how bacterial cell length and pore architecture jointly affect bacterial spreading.
• To elucidate the mechanisms of bacterial transport in different porous media.
• To explore potential applications in separating bacteria based on morphology.

Main Methods:

• Utilized genetically engineered Escherichia coli (E. coli) with tunable cell lengths.
• Employed single-cell tracking in microfluidic devices simulating ordered and disordered porous structures.
• Analyzed bacterial path characteristics, directional persistence, and exploration efficiency.

Main Results:

• Elongated bacteria showed enhanced traversal, straighter paths, and greater directional persistence in ordered porous networks.
• In disordered media, elongated bacteria experienced reduced navigational efficiency due to trapping in dead-end regions.
• Cell morphology and pore geometry were found to interact significantly in governing bacterial transport.

Conclusions:

• Bacterial cell shape and environmental geometry are critical determinants of bacterial transport in porous media.
• The findings offer insights into bacterial behavior in natural and engineered environments.
• A novel mechanism for separating antimicrobial-resistant (AMR) bacteria from susceptible elongated cells using designer porous media is proposed.