Figure 3

Screening of a strain library on the MPP and scale-up of the best performer in lab-scale bioreactors. A: Determination of maximum growth rate and total amino acid titer of a set of genome reduced L-lysine producers (GRLP) using the developed harvest procedure in combination with the Ninhydrin assay (n ≥ 4 biological replicates, cf. Figure 1B and 2C). Strains with significant changes in either parameter compared to the model L-lysine producer DM1933 were determined by one-way ANOVA (p < 0.01) and marked with an asterisk. GRLP45 showed highly elevated amino acid titers in BioLector cultivations while displaying a decreased maximum growth rate. B: Both observations for GRLP45 obtained on the MPP were confirmed in 1 l lab-scale bioreactor experiments (n = 3 biological replicates). Amino acids and L-lysine were quantified in one cultivation run of GRLP45 and DM1933, respectively, using the automated Ninhydrin assay as well as an established LC-MS/MS protocol (n = 3 technical replicates).