Understanding microbial growth by means of simple models and experiments

Microbial growth involves thousands of reactions converting external substrates into biomass. While it may be possible to write down detailed models of these reaction networks, in practice such models are difficult to calibrate and they may not be of much help in gaining a better understanding of the principles underlying bacterial growth. An interesting alternative is the development of coarse-grained models based on the idea of resource allocation, that is, the allocation of cellular resources to the molecular functions enabling microbial growth. While this perspective has its roots in physiological studies of bacterial growth some fifty years ago, recent work in biophysics and microbiology has led to a renewed interest in the use of simple models and experiments for understanding bacterial growth. I will summarize the rationale of resource allocation models and give some concrete examples drawn from work carried out in the BIOP group.