Figure 5
Total GFP yields over a 48 h induction period in 3 L fed-batch cultures. The effect of increased glycerol concentration in the medium and mixed feed induction regimes are demonstrated with standard (squares) and predicted optimal (circles) production conditions. The glycerol concentration was increased from 10 g L-1 (white circles) to 40 g L-1 (grey circles) prior to induction with methanol under DoE-predicted optimal conditions. Also shown are standard conditions (30°C, pH 6.0, 30% DO, methanol induction; white squares), for comparison. Black symbols indicate that the culture was grown with both 40 g L-1 glycerol and a mixed 60% methanol, 40% sorbitol induction regime. Inset are data for pre-induction OD595, mean specific growth rate (μmean; h-1), total and specific yields to allow comparison of the cultures.