The evolution of quorum sensing in bacterial biofilms.

摘要: Bacteria have fascinating and diverse social lives. They display coordinated group behaviors regulated by quorum-sensing systems that detect the density of other bacteria around them. A key example such behavior is biofilm formation, in which communities cells attach to a surface envelope themselves secreted polymers. Curiously, after reaching high cell density, some bacterial species activate polymer secretion, whereas others terminate secretion. Here, we investigate this striking variation first evolutionary model quorum sensing biofilms. We use detailed individual-based simulations competitions between strains differ their production phenotypes. The benefit activating secretion at relatively straightforward: starts upon allowing push lineages into nutrient-rich areas suffocate neighboring cells. But why density? find deactivating biofilms can yield an advantage redirecting resources growth, but occurs only limited time window. predict, therefore, down-regulation will evolve when it coincide with dispersal events, be disfavored long-lived (chronic) sustained competition among strains. Our suggests observed linked differing requirements chronic versus acute infections. This well illustrated case Vibrio cholerae, competes within terminates induces disease course ends mass from host. More generally, work shows balance pivotal evolution sensing.