The purpose of this study was to evaluate the efficacy of replacing animal-derived peptones with non-animal peptones for use in an E. coli biopharmaceutical medium (SuperBroth).  The animal-derived peptone, tryptone peptone, a pancreatic digest of bovine casein[1], was replaced with several non-animal derived peptones¹.  The results of these substitutions support two conclusions.  First, the efficacy of the SuperBroth can be improved by increasing the protein concentration from 32 gm/L (1.0X) to 41.6 gm/L (1.3X); and second Martone B-1 appears to be an excellent substitute for Casein Peptone – Type M.