Motile bacteria in complex fluid environments: liquid-liquid interfaces and viscoelastic polymeric solution

Joonwoo Jeong^1*

¹Department of Physics, Ulsan National Institute of Science and Technology, Ulsan, Korea

* Presenter:Joonwoo Jeong, email:jjeong@unist.ac.kr

I will share a series of our investigations into motile bacteria in a quasi-2D environment that mimics the complex fluid environments of their natural habitats. First, focusing on their motile behaviors near and at liquid-liquid interfaces, we collect and quantify bacterial trajectories and uncover peculiar interactions among bacteria, interfaces, and multi-phases: the isotropic-nematic coexistence phase of lyotropic chromonic liquid crystals and aqueous two-phase systems composed of dextran and polyethylene glycol. Second, we report how motile bacteria interact at a distance via a memory effect in viscoelastic polymeric environments and discuss the statistical physics of trail-bacteria interactions. Given the ubiquity of heterogeneity in biological environments, our findings will help to understand active transport phenomena in complex environments.

Keywords: bacteria, liquid-liquid interface, polymeric environment, active matter