Co‐substrate mannitol feeding strategy design in semi‐batch production of recombinant human erythropoietin production by Pichia pastoris

BACKGROUND The effects of alternative co‐substrate feeding strategies on recombinant human erythropoietin (rHuEPO) production by Pichia pastoris ‐Mut + strain were investigated . RESULTS Five different production strategies were designed and performed in the production phase of the bioprocesses with the use of either mannitol or sorbitol as the co‐substrate. The highest rHuEPO production was achieved as C rHuEPO = 0.65 g L −1 at t =9 h, with the cell concentration C x =55 g L −1 in the production phase; wherein methanol was fed to the bioreactor with a predetermined dynamic feeding rate calculated for constant μ M0 =0.03 h −1 ; and three consecutive pulses of the co‐substrate mannitol were introduced at t =0, 6, and 12 h, so that C Man =50 g L −1 . The overall cell and product yields on the substrates methanol and mannitol were found, respectively, as Y X / St =0.22 g g −1 and Y rHuEPO / St =3.74 mg g −1 . CONCLUSIONS The use of mannitol as the co‐substrate enhanced rHuEPO production and furthermore shortened the bioprocess time. The design of semi‐batch feeding strategy, based on the selection of the substrates and the co‐substrates, and their dynamic feeding into the bioreactor, is important to increase the production and productivity in r‐protein production by Mut + strains of P. pastoris , and the developed strategy would be especially important for therapeutic glycoprotein productions by P. pastoris . © 2013 Society of Chemical Industry