Abstract

I will discuss the behavior of a model describing unicellular organisms living in a continuous culture. We do this mainly numerically, with the help of an extended version of bifurcation analysis adapted to this type of quite complex (structured) population dynamics. The complexity is induced by attaching a whole physiological structure to each of these cells, which in the present case describes the states of their internal cell cycle. Other pathways based on biochemistry would entirely fit into the modeling framework as well. In our example the cycling speed through the cell cycle will depend on the environment, which in a bioreactor environment is just the concentration of some limiting nutrient in the main tank where microbial growth takes place. The model serves well as a basis of multi-scale mathematical modeling of microbial activity, from internal cell biochemistry up to the population level, like distributions of microbial biomasses in the environment. Howev er, medical applications can be covered as well.