Simulation and optimisation of PHB production in fed-batch culture of Ralstonia eutropha

Abstract Fed-batch culture is commonly used to produce partially growth-associated products such as poly-β-hydroxybutyrate (PHB). However, without a proper feeding strategy this culture would not result much higher productivity than bath culture. Therefore, in this study a dynamic optimisation program written in matlab environment was employed to determine optimal feeding rates of carbon and nitrogen sources. A fed-batch mathematical model was developed and validated against experimental data before it was incorporated into the optimisation program. The optimal feeding strategy obtained from the simulation was applied experimentally. The results of this experiment were compared with the results of other fed-batch culture experiments whose feeding strategies were determined based on bioreactor engineering sen se. PHB productivity was increased around 100% using optimal feeding strategy.