Induction of recombinant protein production by pH stress: A novel glucose feeding strategy

Summary

Feeding glucose in response to pH changes was compared to batch trials and glucose estimation by gas data. The cell density was similar for all cases (~8 g/l dry wt). Glucose concentration was estimated to be ~0.006 g/l. The fed-batch by pH strategy had no detectable plasmid loss whereas fed-batch by estimate trials had 99% plasmid retention per generation (78% after 25 generations) and batch trials had only 95% (28% after 25 generations). Protein expression occurred as a consequence of the pH strategy and was not constitutive.