Figure 5
Fermentation of Man5mGM-CSF at 0.015 h-1 (~25% of μ max ). Plotted parameters show dissolved oxygen (DO), pH, temperature, OD600, WCW and biomass during 70 hours of fermentation. The initial batch was grown in FM22 media containing 40 g/l glycerol. Following an increase in DO due to carbon source limitation at around 20 h EFT, the glycerol fed-batch process was initiated. Glycerol was added at 20 g/l/h for 1 hour. The transition phase was initiated by the addition of 1.5 g/l methanol. Simultaneously, the glycerol feed rate was ramped down linearly from 20 g/l/h to 0 over a 3-h period. By the end of the transition phase, the cells were fully adapted to methanol, which was confirmed by a sharp drop in DO. At this point, methanol feeding was initiated. DO was maintained at 40%.