E. coli strain 7107-18 was developed by integrating the T7lac-glmS*54 cassette at the galK locus so that both lactose and galactose could be used to induce gene expression.
Protocols for lactose induction of GlcN production were established in one-liter fermentors and GlcN production reached 17 g/L (Figure 4). This was a 4,000-fold improvement over the wild type E. coli strain. However, the titer was still far below the target for commercialization, which was projected to be over 50 g/L.
Figure 4. Lactose-Induced Glucosamine Production in a One-Liter Fermentor
