Theoretical and experimental recovery of oscillations during batch growth of a mixed culture of yeast in water

Theoretical and experimental evidence of substantial damped oscillations during batch interaction of two strains of Saccharomyces cerevisiae grown as a mixed culture in pure (distilled) water is provided. The experimental results show that in the limited nutrient conditions of growth in pure water both strains coexist if the initial concentration ratio between the two strains is 1:1. A new theoretical model that was originally developed for recovering the growth of single species in isolation is extended and applied to the two strains of yeast competing over a common ecological niche. The model solutions are shown to recover all the qualitative features captured in the experiments.