Biophysics of environment sensing by motile microorganisms
Dr. Remy Colin
The ability to move and especially to navigate in the environment is a major player of the organization of microbial populations, be it in biofilm or aggregate formations in multiple species (from Escherichia coli to Myxococci), or during swarming, when a bacterial population propagates on a gelatinous surface. At low cell density, one of the main physiological functions associated with motility is chemotaxis, a navigation strategy which consists in the cells biasing their random walk to move towards favorable environmental conditions, monitored by a specific biochemical sensory pathway.
Current understanding of this bacterial sense of smell remains largely restricted to the average behavior of a single cell, mostly in E. coli. Actual environments however feature dense bacterial populations where physical interactions between cells notably allow for the emergence of collective motilities (swarming, twitching). Moreover, even cells of clonal populations display some level of individuality, featuring a large variability of swimming behaviors both from cell to cell and for one cell over time, which is predicted to be central in the global performance of the dilute population. The goal of our work is to understand how these physical constraints modulate and shape chemotactic navigations.
R. Colin*, K. Drescher and V. Sourjik,*, Chemotactic behavior of Escherichia coli at high cell density, Nature Communications (2019) 10, 5329 doi:10.1038/s41467-019-13179-1
R. Colin1,*, C. Rosazza1, A. Vaknin and V. Sourjik* Multiple sources of slow activity fluctuations in a bacterial chemosensory network. eLife (2017) 6, e26796, doi:10.7554/eLife.26796
R. Colin and V. Sourjik Emergent properties of bacterial chemotaxis pathway. Current Opinion in Microbiology (2017) 39, 24, doi: 10.1016/j.mib.2017.07.004
L. Laganenka, R. Colin and V. Sourjik, Chemotaxis towards autoinducer 2 mediates autoaggregation in Escherichia coli, Nature Communications (2016) 7, 12984, doi:10.1038/ncomms12984
R. Colin*, R. Zang and L.G. Wilson, Fast, high-throughput measurement of collective behaviour in a bacterial population, Journal of the Royal Society Interface (2014) 11, 20140486, doi:10.1098/Rsif.2014.0486