FIG 4.

Fed-batch fermentation profile of CgS1/pEC-SB for ALA production. Fermentation was performed in a 1-liter baffled shake flask containing 100 ml modified CGXII medium, at 30°C and 180 rpm, and the pH was maintained at approximately 6.5. The initial glucose concentration was about 40 g/liter. The precursor glycine was added at 2 g/liter every 12 h. For clarity, a representative curve from three independent experiments is shown, with standard differences (relative standard deviations [RSDs]) of less than 10%.