Development of a structured dynamic model for the production of polyhydroxybutyrate (PHB) in Azohydromonas lata cultures

The development of an accurate model representation of the fermentative production of polyhydroxybutyrate (PHB) is a prerequisite for the optimal operation and control of the microbial process. In the present work, a macroscopic model is developed to quantify the intracellular production of PHB in Azohydromonas lata bacteria. The proposed two-compartment structured model provides an accurate prediction of the metabolic and macroscopic phenomena occurring in A. lata bacterial cultures. Precisely, the proposed dynamic model accounts for biomass growth, polymer accumulation, carbon and nitrogen sources utilization and oxygen mass transfer rates. It is shown that the model can closely describe the time evolution of the bacterial culture via its direct comparison with experiments performed in flasks or/and a bioreactor. Moreover, it is shown that the model can be used as a simulation tool for process optimization and scaling-up studies of the PHB fermentative production in A. lata cultures.

► Dynamic model for the effect of culture conditions on the culture growth.
► Dynamic model for the effect of culture conditions on the PHB production mechanism.
► Transition from biomass-growth dominant phase to PHB-accumulation dominant phase.
► PHB inhibition effect on the biomass growth.
► Model-based scaling-up study of the PHB fermentative production in Azohydromonas lata cultures.