Module 4: Motility and chemotaxis

How do bacterial cells swim in liquid? How do they become clustered at locations favorable for their growth?

bacterial cell with flagella extending from body and forming single corkscrew for propulsion
(top) uniform distribution of cells in liquid and (bottom) redistribution of cells to form higher density in the direction of a diffusible gradient of attractant
(left) bacterial cell trajectory swimming in liquid and with periods of tumbling and swimming. (right) Modifed trajectory with increased swim times in direction of increasing concentration of attractant