Mathematical investigations of growth of microorganisms in the gradostat

Microbial ecosystems with spatial distribution of substrate (nutrient) supply in the form of gradients have been studied in a laboratory system called the gradostat, which is a series of coupled chemostats. We investigate analytically and numerically a mathematical model, similar to the one for a single chemostat based on Michaelis-Menten kinetics, of the growth of one species of microorganisms in the gradostat in the presence of one limiting substrate and two limiting complementary substrates. Our analysis predicts various patterns of spatial distribution of microorganisms at steady state and suggests further experiments to be performed with the gradostat.This work was supported by the Deutsche Forschungsgemeinschaft