The use of fed batch cultivation for achieving high cell densities in the production of a recombinant protein in Escherichia coli.

The production of the fusion protein staphylococcal protein A/E. coli beta-galactosidase in Escherichia coli was studied in batch and fed batch cultivations. Batch cultivation of a recombinant E. coli strain yielded a final cell dry weight of 16.4 g l-1 with a final intracellular product concentration of recombinant protein corresponding to approximately 38% of the cell dry weight. Fed batch cultivation made it possible to increase the final cell dry weight to 77.0 g l-1. The intracellular product concentration (25%) was lower as compared to batch cultivation resulting in a total concentration of recombinant protein of 19.2 g l-1.