Abstract:

Abstract:Objective  To optimize the fermentation condition of large scale fermentation of human oncostatin M(hOSM)  with engineering strain of Pichia pastoris. Methods The optimal pH condition of hOSM expressed in the methylotrophic yeast Pichia pastoris X-33 in tube-scale was determined and fermentation of hOSM was performed in an 80 L fermentor in a fed-batch mode for three times.The pH value, culture medium, dissolved oxygen, temperature, methanol feeding speed, initial biomass and etc were focused mainly.hOSM was analyzed by SDS-PAGE.Results  In the FM21 medium of pH 5.0, when a cell yield of 190 g/L wet weight was achieved, methanol induction phase began.In the fermentation broth of pH 5.5, the temperature was controlled at 28 ℃, a stirring speed of up to 650 r/min, the pressure of fermentor was 10 P, dissolved oxygen above 25% and the supply speed of methanol was 9.3 mL?h-1?L-1 initial fermentation volume, after methanol induction for about 36 h, the expression level of hOSM reached 280 mg/L. Conclusion  OSM is successfully obtained through genetic engineering for large scale production of hOSM for following biological functions.

Key words:  oncostatin M, Pichia pastoris;fermentation