Quorum sensing is a term that refers to the coordinated behavior exhibited by a population of bacteria. The phenomenon involves a communication between the bacterial members of the population and, via a triggering signal, the carrying out of a particular function.

Examples of quorum sensing are the coordinated feeding behavior and the formation of spores that occur in large populations of myxobacteria and actinomycetes. Quorum sensing also occurs in bacterial biofilms, where signals between bacteria can stimulate and repress the production of the extracellular polysaccharide in different regions of the biofilm, and the exodus of portions of the population from the biofilm, in order to establish a new biofilm elsewhere.

Historically, the first indication of quorum sensing was the discovery of the chemical trigger for luminescence in the bacterium Photobacterium fischeri in the 1990s. At high densities of bacteria, luminescence occurs. Light production, however, does...