autoinducer

microbiology

1. :  a molecule produced and secreted by bacteria that when present at a threshold concentration in a population of bacteria signals genetic expression in the same bacteria from which it was produced When a crowd of bacteria and their autoinducers become dense enough, the lights in all the bacteria switch on at once. — Wendy Orent, Discover, July/August 2009 The synchronous response of bacterial populations to autoinducers confers a form of multicellularity to bacteria. — Andrew Camilli and Bonnie L. Bassler, Science, 24 Feb. 2006 ◆Autoinducers are involved in the quorum sensing used by some bacteria to detect their population density and coordinate group actions (such as the formation of biofilms).