Fig. 6
Comparison of the relative RMSEPred, full for glycerol, CDW, and pH value for the PLS models generated in Berg et al. [41] and this study. Backward diagonal hatched columns describe RMSEPred, full, based on the complete prediction dataset, except the culture holding the initial concentration of the respective secondary substrate according to Jeude et al. [53] (− 100%). Forward-hatched columns describe the RMSEPred, full, calculated for spectral online datasets including only the fluorescence intensities (Fl). For the diagonal cross-hatched columns, additionally, the cultures with the highest initial concentration were excluded. The individual values are given in Additional file 2: Table S1