The past 30 years have brought significant progress in the design and manufacture of cell culture media as well as in the types of components used. With these advances, the biopharmaceutical industry improved its processes — from producing just a few milligrams of product per liter of culture to ≥10 g/L. Since the early days of microbiology, peptones have been used widely as a basic ingredient of microbial media. In the 1990s, peptones were introduced as a substitute for serum…