Modeling and Simulation of Polyhydroxybutyrate Production by Protomonas extorquens in Fed-batch Culture

Modeling and simulation of Polyhydroxybutyrate (PHB) production by Protomonas extorquens in fed-batch culture were conducted in this research. The fed-batch model, developed for this process, employed a kinetic model proposed by other researchers. Several kinetic models were investigated to choose the best model. The criterion for this selection was goodness of fit (δ2). Haldane kinetic model was selected since it leads to the lowest δ2. Experimental data that have been used in this study were extracted from literature. The kinetic model was then incorporated into the process model. The values of process model parameters were estimated by employing an optimization routine developed in this study and using two sets of experimental data. These data were obtained applying two different methods of fed-batch cultivation. The values of δ2 for these two methods were 2.5 and 0.0016 respectively. Finally, simulation results were compared with two other sets of experimental data to validate the model.