Bacterial Colony Spreading via Surface Tension Driven Flows

Dispersal and range expansion is critical to the survival of bacteria. Bacterial colonies grown on surfaces have developed various strategies to spread, such as swarming, gliding or twitching. Here we report a novel spreading behavior in Pseudomonas aeruginosa that does not rely on single-cell motility but requires surface-tension driven flows maintained by cooperative synthesis of bio-surfactants. We combined fluorescence microscopy imaging, genetic engineering, and computational modeling to reveal the biophysical mechanism underlying this behavior. Our findings shed new light on the cooperative behavior and long-range transport of bacteria.