Development of simple kinetic models and parameter estimation for simulation of recombinant human serum albumin production by Pichia pastoris
In order to describe and predict the growth and expression of recombinant proteins by using a genetically modified Pichia pastoris, we developed a number of unstructured models based on growth kinetic equation, fed-batch mass balance and the assumptions of constant cell and protein yields. The growth of P. pastoris on both glycerol and methanol could be represented by Monod kinetic equation. A simple simulation methodology and developed models were shown to satisfactorily describe both growth and production of recombinant human serum albumin (rHSA) using a genetically modified P. pastoris MutS strain. The obtained parameters from curve fitting were reasonable and could be acceptable. Moreover, the same parameter sets obtained by the experiments indicated the rigidity and consistency of the developed models and fermentation approach of this study. With correlation coefficients (r2) exceeding 0.99, the models were able to simulate and predict the cell growth behavior and recombinant protein production by P. pastoris without requiring complex models.
Key words: Exponential feed, growth modeling, Monod kinetic equation, Pichia pastoris, recombinant human serum albumin.