Laboratoire Matière et Systèmes Complexes

March 22th 2021. 11h30

There will be a live diffusion with Zoom. Contact Michael Berhanu to attend the video seminar.

Biophysics of bacterial navigation

Dr. Rémy Colin

Project Group Leader

Max Plank Institute for terrestrial microbiology Marburg, Germany

Abstract :
Many bacteria swim using flagella to not only randomly explore, but also navigate in the environment, in order to reach optimal conditions for growth and avoid poisons. To this end, a dedicated biochemical pathway measures physicochemical gradients as the cell swims and modulates the changes of swimming direction to bias the motion towards ‘’preferred’’ conditions. Originally thought of as a single cell behavior, this chemotactic sensing has been increasingly realized to be an integral part of the buildup of mono- and multi-species bacterial communities via the perception of signals released by other cells or even the host organism. Understanding the integration of the signal perception into a population behavior is a fascinating multi-scale problem, with applications even beyond bacteria, that mobilizes all the strength of statistical physics. During this talk, I plan to touch on two aspects of this problem. The first focuses on the single cells, and ask how the micron-sized bacteria cope with and even exploit noise to enhance signal perception by the pathway. The second zooms out to the population behavior and asks how physical interactions between cells modulate the navigation in environmental gradients.