Characterisation and modelling of oscillatory behaviour related to reuterin production by Lactobacillus reuteri.

During reuterin production by Lactobacillus reuteri in a chemostat, the growth, substrate and metabolite concentrations showed oscillatory behaviour. The sensitivity of L. reuteri towards reuterin was shown to be a possible explanation of the oscillatory behaviour. A deterministic mathematical model consisting of four coupled differential equations describing the concentrations of biomass, glucose, glycerol and reuterin with time was developed. With a set of parameter values determined from batch experiments, the model was able to predict both oscillatory and steady state behaviour in a chemostat by changing the input variables. In a batch system, the model was able to give a satisfactory description of the glucose and glycerol concentrations but not of the biomass and reuterin concentrations. Mathematical modelling of the system was shown to be an effective and systematic approach in exploring a complex biological system.