LAUSR

Significance How is it possible that microbial populations can robustly adapt to an immense variety of environments when their regulatory circuitry is extremely noisy and of limited accuracy? We propose that the remarkable adaptability of microbial populations can be explained by the combined effects of two experimentally observed phenomena: 1) that gene regulation is inherently noisy, causing individual cells to randomly switch between different phenotypic states, and 2) that the slower cells grow, the noisier they become. As a consequence, whenever cells encounter a new environment, they stochastically explore new phenotypes, only to stabilize after reaching a fast-growing phenotype. We propose that this growth rate dependent stability may play an important role in adaption of all microbes.