Recombinant protein expression in Pichia pastoris in a bioreactor via semi-continuous mode
Pichia pastoris has been successfully used as an efficient expression system for heterologous protein production. Herein, we report the development of a semi-continuous process to improve the production of recombinant proteins in P. pastoris by its cultivation in a BIONET’s F1 benchtop 3-liter bioreactor equipped with a continuous process module (CPM).
Six repetitive batches were conducted in a semi-continuous process by replacing 2/3 of the culture every 72-96 h. The overall process in a 3-liter culture yielded a protein concentration of 0.28±0.13 mg·mL−1, taking 650 h to obtain 6±0.5 g of total target protein. On the contrary, the obtention of the equivalent amount of protein with a fed-batch mode would require around 1100 h of total time, including the inoculum preparation, the non-induced fermentation stage and the expression stage. Therefore, a reduction of the operation time and of the operation cost is evident when using a scalable semi-continuous fermentation strategy. These results suggest there is potential for the development of cost effective processes for the expression of recombinant proteins in P. pastoris in semi-continuous mode as an alternative to the productive continuous process mode, that is not available when low dilution rates are required due to the lack of available pumping technology.