Fig. 5

Fed-batch fermentation for 5-ALA production from glucose using strains CA and CA1P4. Black filled labels represent strain CA and green open labels represent strain CA1P4. Square, OD_600nm; circle, glucose consumption; triangle, glycine consumption; diamond, 5-ALA; star, lactate. Dotted line represents simulated growth curve based on OD_600nm data. Cultivation was performed in 5-L bioreactors with fermentation medium. IPTG (0.1 mM) and glycine (4 g/L) were added when OD_600nm reached approximately 40 to induce gene expression and 5-ALA biosynthesis. Glucose and glycine were continuously fed into the bioreactor during the fermentation. The pH was controlled at 6.5 initially and switched to 6.0 at 15 h. The dissolved O₂ was maintained at 30% initially and switched to 10% at 18 h