Fig. 3

Glycerol fed-batch cultivation of E. coli FUS4.7 R/pC53BC/pJNT-aroFBL in shake flasks. The initial glycerol concentration was 5 g l⁻¹. After 24 h of cultivation the cultures were induced with 0.5 mM IPTG (final concentration) and the shake flasks were transferred from 37 to 30 °C before adding pulses of ~ 5 g l⁻¹ of glycerol every 12 h. To adjust the pH, sodium bicarbonate (30 mM) was added every 24 h as well as 15 mM of ammonium sulfate. The concentrations of glycerol (empty circles) and, l-PAPA (empty squares) were determined by HPLC. OD₆₀₀ values are presented as filled squares. The cultivations were performed in triplicate and the mean values and standard deviations are given