Emergence of ion-channel mediated electrical oscillations inE. colibiofilms

AbstractBacterial biofilms are unusual examples ofactive excitable matter. They grow due to cell divisions (a motile process) and can modulate their membrane potentials. Knowledge on how the clinically relevant Gram-negative bacterium,Escherichia coli, uses its membrane potential dynamics is scarce. We report for the first time, community-level synchronized membrane potential dynamics in three-dimensionalE. colibiofilms. We reveal that the voltage-gatedKch-potassium channel mediates both local spiking of singleE. colicells and long-range coordinated electrical signaling inE. colibiofilms. Our data provide robust information on the membrane potential dynamics inE. coliand presents an experimental method for studying collective electrical oscillations inE. coli. The electrical phenomena are explained using Hodgkin-Huxley and 3D fire-diffuse-fire agent-based models. The electrical oscillations suggest a mechanism by whichE. colibiofilms become resilient to light stress.