Economical parallel protein expression screening and scale-up in Escherichia coli

A novel microfermentation and scale-up platform for parallel protein production in Escherichia coli is described. The vertical shaker device Vertiga, which generates low-volume high density (A(600) approximately 20) Escherichia coli cultures in 96-position deep-well plates without auxiliary oxygen supplementation, has been coupled to a new disposable shake flask design, the Ultra Yield flask, that allows for equally high cell culture densities to be obtained. The Ultra Yield flask, which accommodates up to 1 l in culture volume, has a baffled base and a more vertical wall construction compared to traditional shake flask designs. Experimental data is presented demonstrating that the Ultra Yield flask generates, on average, an equivalent amount of recombinant protein per unit cell culture density as do traditional shake flask designs but at a substantially greater amount per unit volume. The combination of Vertiga and the Ultra Yield flask provides a convenient and scalable low-cost solution to parallel protein production in Escherichia coli.