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 (A₆₀₀ ∼ 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^TM flask, that allows for equally high cell culture densities to be obtained. The Ultra Yield^TM 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^TM 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^TM flask provides a convenient and scalable low-cost solution to parallel protein production in Escherichia coli.