Fig. 4

Radar plots of the normalized fluorescence intensities exhibited of the microbial population during the L-phenylalanine fed-batch production from glycerol with E. coli 4RP. The median fluorescence signals were averaged for the six process phases in the initial batch, early and late biomass production and the induction/early, middle and late product formation. Higher values indicate a higher expression of the corresponding cellular phenotypes in the general stress response (blue plot), growth behavior (green plot), oxygen limitation (orange plot) and product formation (red plot). The white background represents the initial batch phase, the orange background the biomass production phase and the grey background the product formation phase