Development of a chemically defined medium that allows high growth rates and protein expression in E. coli.

Escherichia coli (E.coli) is the workhorse of the biotechnology industry and has achieved this position because it can be easily engineered, a variety of expressions system exist and it exhibits fast growth. Historically, E. coli has been cultivated in complex medium such as LB and Terrific broth where this microorganism can achieve high growth rates and high yields of protein production.  However, these media have undesirable traits such as containing animal derived components, color, increased foaming and lot to lot variability. Here we report the development of Sheff-Coli CD II, a chemically defined medium for E. coli. This medium was developed by screening and optimizing different components using micro titer scale culture through to bioreactors. The utilization of Sheff-coli CD II media allowed strains of E. coli to achieve growth rates up to twice of those achieved in minimal media and show protein expression levels comparable to those in LB.  Moreover, Sheff-coli CD II is clear and colorless in solution, and can be autoclaved when non-reducing sugars are used.