Production of Single-Chain Variable Fragment Antibody (scFv) in Fed-Batch and Continuous Culture of Pichia pastoris by Two Different Methanol Feeding Methods

This study examined the effects of two methods of methanol feeding, DO-stat and methanol concentration control, in fed-batch and continuous cultures of Pichia pastoris on cell growth and single-chain variable fragment antibody (scFv) expression. By maintaining the methanol concentration at 3.9 g l–1 in fed-batch culture, a scFv concentration of 198 mg l–1 was obtained. In continuous culture using both methanol feeding methods, the scFv concentration in the fermentation broth increased with a decreasing dilution rate. A maximum scFv concentration of 810 mg l–1 at a dilution rate of 0.0094 h–1 was obtained by maintaining the methanol concentration at 3.9 g l–1. Although the specific methanol consumption rate was the same for both methods, the specific productivity of scFv was higher in methanol concentration control from 0.0094 to 0.049 h–1 than it was in DO-stat control. Therefore, continuous culture with methanol feeding by the concentration control method shows promise for the industrial scale production of recombinant proteins by Pichia pastoris.