Efficiencies of Growth and Angiostatin Expression in Cultures ofPichia pastoris Fed with Mixed Carbon Sources

Different carbon sources, glycerol, sorbitol, acetate and lactate were added together with methanol in the induction phase of Pichia pastoris culture for angiostatin production in a 5-L fermentor. Mass balances were carried out for different processes, yield coefficients were discussed and stoichiometric coefficients were estimated to compare the efficiency of different carbon sources. Glycerol had the highest reduction degree among the four non-methanol carbon sources, as well as higher energetic yield coefficient for biomass production ( ) and lower respiratory quotient (RQ), indicating that glycerol was a more efficient carbon source for biomass formation than the other three non-methanol carbon sources. Lactic acid, a non-repression carbon sources, had lower reduction degree, but achieved the highest energetic yield coefficient for angiostatin production ( P).