Production of granulocyte-macrophage colony stimulating factor (GM-CSF) by high cell density fermentation of secretory recombination Escherichia Coli

Abstract

High cell density fermentation production of recombinant human granulocyte-macrophage colony stimulating factor (GM-CSF) was studied in an Escherichia coli secretory expression system. By using glycerol instead of glucose as a carbon source and feeding in a specific fed-batch mode and by controlling the temperature at about 30°C and maintaining the dissolved oxygen level at 20∼25% saturation, cell density increased from 30 to 91.8 g l −1, the production of recombinant GM-CSF remained high and the fermentation time was reduced from 45 to 30 h. Recombination GM-CSF was purified by hydrophobic column-molecular sieve-ion exchange column chromatography. The expression of recombinant GM-CSF was not affected by fermentation methods, the production of GM-CSF reached 28.04% (about 1.68 g l −1) and 27.51% (about 1.64 g l −1) of total somatic proteins for high cell density and normal fermentation, respectively. The corresponding value for specific activity of GM-CSF was 2.6×10 7, and 2.4×10 7, respectively.