Microbial communities are continuously exposed to unpredictable changes in their environment. To thrive in such dynamic habitats, microorganisms have developed the ability to readily switch phenotypes, resulting in a number of differently adapted subpopulations expressing various traits. In evolutionary biology, a particular case of phenotypic heterogeneity that evolved in an unpredictably changing environment has been defined as bet-hedging. Bet-hedging is a risk-spreading strategy where isogenic populations stochastically (randomly) diversify their phenotypes, often resulting in maladapted individuals that suffer lower reproductive success. This fitness trade-off in a specific environment may have a selective advantage upon the sudden environmental shift. Thus, a bet-hedging strategy allows populations to persist in very dynamic habitats, but with a particular fitness cost. In recent years, numerous examples of phenotypic heterogeneity in different microorganisms have been observed, some suggesting bet-hedging. Here, we highlight the latest reports concerning bet-hedging phenomena in various microorganisms to show how versatile this strategy is within the microbial realms. This article is categorized under: Infectious Diseases > Molecular and Cellular Physiology.
Keywords: adaptation; bet-hedging; evolutionary strategy; persisters; phenotypic heterogeneity.
© 2021 The Authors. WIREs Mechanisms of Disease published by Wiley Periodicals LLC.