The yeast Pichia pastoris, has been successfully used as an efficient system to produce heterologous proteins [1]. Herein, we report the development of a semi-continuous process to improve the production of recombinant proteins in P. pastoris in BIONET’s F1 bench-top 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±0.13mg·mL−1, where over 650h were required to obtain 6±0.5 g of the total target protein, while the equivalent amount of protein in a fed-batch would require around 1100h in total, including inoculums, non-induced stage and expression stage, achieving a reduction in the operation time and cost when compared with the semi-continuous process with fed-batch mode. These results suggest that there are promising possi bilities to develop cost-effective processes, even when conditioned by low dilution rates required by the culture, for the expression of re combinant proteins in P. pastoris in semi-continuous mode as an ap proximation to a continuous process.
