Affordable Access

Secondary metabolites can change competition results towards coexistence in the chemostat

  • Mathematics
  • Medicine


For microbial species competing for one limiting resource in a chemostat, mathematical models and in particular the competitive exclusion principle (CEP) predicts survival of only one species in any case. Quantitative experimental data from our model system related to genetic disease Cystic Fibrosis alludes to the coexistence of at least two competing species. We developed a new mathematical model (extension of the classical chemostat) to comply with the experimental phenomena by including species specific properties of the microorganisms of concern. We will present the mathematical tools and the analysis fo the mathematical model, consisting of a four-dimensional system of nonlinear ordinary differential equations as well as computed simulations for experimental data. We found that the dynamic of the system changes in a fundamental way, if interspecific competition is included; a Hopf bifurcation occurs for an appropriate choice of parameters. Experimental data serve as basis of knowledge for the applied assumptions. These are a) one species produces a secondary metabolite, b) the metabolite has a growthinhibiting effect, but can also be exploited as a secondary carbon resource, c) some of the species could compete directly (e.g. via toxin production), and d) a lethal inhibitor could be introduced that cannot be eliminated by one of the species and is selective for the stronger competitor.

There are no comments yet on this publication. Be the first to share your thoughts.


Seen <100 times

More articles like this

Predator — mediated coexistence in a chemostat: Co...

on Mathematical Modelling Jan 01, 1987

How flocculation can explain coexistence in the ch...

on Journal of biological dynamics January 2008

Species coexistence under resource competition wit...

on Theoretical Population Biology Jan 01, 2010

Coexistence of S. cerevisiae and E. coli in chemos...

on Biotechnology and bioengineeri... November 1986
More articles like this..