Adaptive metabolic strategies explain diauxic shifts and promote species coexistence
Date:
This talk has been held during the Conference on Complex Systems 2018.
After a short introduction about consumer-resource models and the competitive exclusion principle, I have illustrated the latest results of my work published in a preprint that will soon be submitted to a peer reviewed journal.
Abstract
Competitive systems are most commonly described mathematically using MacArthur’s consumer-resource model, leading to the “competitive exclusion principle” which limits the number of coexisting competing species to the number of available resources. Nevertheless, several empirical evidences - in particular bacterial community cultures - show that this principle is violated in real ecosystems. Another experimental evidence that cannot be explained in this framework is the existence of diauxic (or polyauxic) shifts in microbial growth curves: bacteria consume resources sequentially, using first the one that ensures the highest growth rate and then, after a lag phase, they start growing slower using the second one. By introducing adaptive metabolic strategies whose dynamics tends to maximize species’ relative fitness, we are able to explain both these empirical evidences, thus setting the paradigm for adaptive consumer-resource models.