Physics of bacterial motility

photo of migrating bacteria
Mass swarming: for 10-12 hours, the bacteria only multiply in the bright spot which can be seen in the lower right. But then, within 2-3h, they collectively migrate outwards (branched structures).

with Marc Hennes, Julien Tailleur, Kassem Hamze, Lina Hamouche, Soumaya Laalami, Harald Putzer, Simone Séror, Barry Holland, Mehdi Banaha, …

Most bacteria are capable of amazing collective behaviour; mass swarming is a way to rapidly colonize a surface, and likely a first step in the formation of biofilms, which are structures adopted by bacteria that allow them to resist antibiotics, the immune system (inside the body), cleaning (sewerage systems, medical instruments) et caetera. The mecanisms involved in mass swarming are still not understood. Some keys to an explanation might just have been found by a team of genetical biologists around Kassem Hamze, Daria Julkowska, Simone Seror and Barry Holland of the IGM in Orsay: migration is linked to the production of a powerful surfactant called Surfactine, and to hypermotility of the swarming cells.

We are investigating the forces at play at the onset and during migration, and studying the influence of environmental parameters such as humidity, gel stiffness and the like.

*B. subtilis* swarm on a gel surface

Last modified: 18 Jul 2020