The predominant mode of growth of most bacteria in natural and engineered environments is as a surface-associated community encased in an extracellular matrix, called a biofilm. When conditions within the biofilm become unfavourable, bacteria must be able to disperse to escape and colonize new habitats.

The dispersal response of bacterial biofilms is regulated through the production and perception of extracellular and intracellular signalling molecules and in response to environmental cues such as changes in nutrient concentrations. Such signals and cues are translated into changes in gene expression that induce effectors, such as enzymes and surfactants, which break down the biofilm matrix and prepare bacteria for planktonic growth.

In addition to releasing bacteria to colonize new sites, dispersal is associated with the formation of genetic variants that may be altered in traits which are important for colonization of and competition in new habitats.

The sessile (biofilm) and motile (dispersal) phases of bacterial growth have close analogies to the lifestyles of colonial and holometabolous eukaryotes, including the generation of variants in the dispersal propagules. Biofilms may therefore be useful experimental tools to further explore ecological and evolutionary theories surrounding organisms with sessile and motile life phases.