Kinetic modelling of recombinant Pichia pastoris harboring multiple porcine insulin precursor (PIP) gene dosages was studied when the cells were grown in the fed-batch culture. The key parameters of this kinetics were estimated

including specific cell growth rate (h-1)

PIP production rate (g·g-1·h-1) and substrate consumption rate (g·g-1·h-1) with nonlinear curve fit by Origin8.0. The results showed that both growth-associated production coefficient ( ) and growth-associated metabolism coefficient (k1) increased with increasing copy numbers. The expression level of PIP reached the highest at the copy number of 12. These results suggested that rapid growth and lower metabolic burden of a high copy number effectively improved the production rate of target proteins. Furthermore

the predicted values based on the established kinetic model were in good agreement with the experimental data

indicating that the kinetic model could be used to describe recombinant PIP production process in fed-batch fermentation mode.