Chemically defined media development for Escherichia coli fermentation

Changing from a medium containing peptone and yeast extract to chemically-defined medium (CDM) can have numerous benefits including the elimination of complex raw materials from the process, reduction in batch-to-batch variability, insulation against vendor initiated changes, and the potential to learn more about raw material interactions with fermentation outcomes.  Two 10-L fementations and a Definitive Screening Design (DSD) using an ambr250 small-scale (250 mL) bioreactor system were performed.  The initial 10-L proof of concept fermentation showed acceptable growth and titer when using CDM versus hydrolysate-containing medium.  The DSD was then performed which indicated that adjusting certain parameters may prove beneficial to growth and titer.  A follow up 10-L fermentation was performed using the optimized parameters from the DSD.  Future development efforts are discussed.