Consequences of noise in bacterial communication

Bacterial quorum sensing is a phenomenon associated with secreting signaling molecules called autoinducers into the extracellular environment. Individual bacteria can regulate gene expression by detection and response to autoinducers. On the other hand, gene expression which involves a series of biochemical interaction is a stochastic process. Noise in gene expression can lead to emergence of different subpopulations with distinct behaviors within an isogenic population of bacteria.We model the case in which production of an exoenzyme under quorum sensing regulation can increase the growth rate of individuals. This exoenzyme, representing a public good, can freely diffuse into the environment and breakdown a substrate. We verify under what conditions heterogeneity in communication networks and division of tasks between two different phenotypes are metabolically beneficial for the whole population. We show the optimum initial ratio of these two subpopulations depends on the energetic cost associated with each task and the benefit provided by the trait.