Fig. 4

Fed-batch production of l-PAPA in a 30 l bioreactor. Cell dry weight (CDW, empty circle), glycerol consumption (g l⁻¹, empty triangle) and l-PAPA concentration (g l⁻¹, empty square) were monitored for E. coli FUS4.7R/pC53BC/pJNT-aroFBL. The strain was grown in minimal media with an initial concentration of 8.1 g l⁻¹ glycerol. The glycerol feed started after 11.4 h (red solid line, first pulse of l-Phe and l-Tyr and induction with 0.5 mM IPTG) and the feed was adjusted to maintain a concentration of 0.6–1.0 g l⁻¹ glycerol. A second pulse of l-Phe and l-Tyr (dotted line) and a third pulse of l-Phe and l-Tyr (dash line) were fed to allow biomass formation. The result of one fermentation is presented with mean values and deviations of three technical replicates