Lecture: Community patterns in consumer-resource models

Competitive eco-systems are widespread and most commonly they are described mathematically using MacArthur’s consumer-resource model, leading to so called the “Competitive Exclusion Principle”, which limits the number of coexisting competing species to the number of available resources. Nevertheless, several empirical evidences – for example bacterial community culture experiments – show that this principle is violated in real ecosystems.

Another experimental evidence involving microbial populations that cannot be explained in this framework is the existence of diauxic (or polyauxic) shifts in microbial growth curves: microbes can adapt their metabolic strategies to the availability of different resources in the environment: when exposed to different sugars they often consume them sequentially resulting in population growth curves with distinct phases of growth rates.

In this talk I share ideas from our recent works [1-2], where we show that by introducing adaptive metabolic strategies to consumer-resource models we can reproduce diauxic shifts in agreement with experimental observations and it allows consumer-resource models to violate the “Competitive Exclusion Principle”.

[1] Pacciani-Mori, L., Giometto, A., Suweis, S., & Maritan, A. (2020). Dynamic metabolic adaptation can promote species coexistence in competitive microbial communities. PLoS computational biology, 16(5), e1007896.

[2] Pacciani-Mori, L., Suweis, S., Maritan, A., & Giometto, A. (2021). Constrained proteome allocation affects coexistence in models of competitive microbial communities. The ISME journal, 15(5), 1458-1477.