Adaptation in competitive microbial communities

Colony of Legionella pneumophila observed with SEM microscopy (false colors)

The time evolution of microbial populations growing on externally supplied resources is generally modeled using MacArthur’s consumer-resource model, both when considering a system of one or several species. An assumption that is always implicitly made in the literature, when using this model, is that the “metabolic strategies” (also known as “resource preferences”), i.e. the rates at which each species uptakes the available resources, are constant parameters that do not change over time. However, we know since the ’40s that microbes do change the way in which they absorb nutrients from the environment, giving rise to the famous phenomenon of diauxic shifts.

My current main research interest consists in building a new kind of consumer-resource models where metabolic strategies are adaptive (i.e. can change over time depending on the environmental conditions), and studying how this changes our knowledge of consumer-resource models and microbial competition in general. In particular, I’m interested in seeing how using adaptive metabolic strategies can help us understand better how single species can grow in environments with multiple resources and how complex communities of several species can coexist.