Fermentation conditions of chymosin by recombinant Pichia pastoris
The optimal conditions for producing chymosin in 5L fermenter by recombinant Pichia pastoris Gsl 15/pPICZaA-Prochy were determined in order to offer technical bases for pilot scale production. After induction for 84h, the highest enzyme activity (152SU/ml) was achieved with batch culture, in which, lOg/L sorbitol was added at the beginning of induction phase, methanol concentration was kept at 0.1%, 10g/l peptone was added every 12h, pH value was kept at 3.0 and the concentration of oleic acid was 0.2%. The purification of chymosin was analyzed by sodium dodecyl sul-fete benzene agarose gel electrophoresis (SDS-PAGE). Under the concentration of salt ions at 2mol/L and flow rate 2.5mL/min, the recovery rate of chymosin was 82.33% and the enzyme sample was concentrated by 20 folds.
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万方数据
维普
