Increasing Temperature Favors Slower-Growing Bacterial Species

Temperature is among the cardinal environmental variables which affect the growth and survival of microorganisms. Although the effects of temperature on the growth rates and metabolic activities of individual species is a central focus of microbiology, the manner in which temperature regulates competition between species is less well understood. Using a simple adaptation of the Lotka-Voltera competition models, we hypothesize that temperature should have generic effects on microbial competition, such that slower-growing species should consistently be favored by increasing temperature. We demonstrate that this prediction holds true in experimental pairwise competitions between a diverse set of species, and discuss how a community-wide death rate and the growth rates of the individual species interact to shape competitive landscapes. Finally, we show that pairwise dynamics are predictive of competitive outcomes in more complex communities, suggesting it should be possible to make general predictions for how communities might react to warming environments.