Peptides required for the growth of Lactobacillus bulgaricus.

Jones, K. M. (The Rockefeller Institute, New York, N. Y.) and D. W. Woolley. Peptides required for the growth of Lactobacillus bulgaricus. J. Bacteriol. 83:797-801. 1962.-Lactobacillus bulgaricus 09 had an absolute requirement for growth for a suitable peptide, which was satisfied by trypsinized casein or hemoglobin. Digests of globin and the alpha and beta chains derived from it showed similar activity to hemoglobin digests. Each of four highly purified peptides of different amino acid composition isolated from the alpha chain of globin had activity. Each active peptide had seven or more residues; smaller peptides were inactive. The requirement for L. bulgaricus was not one for strepogenin because some substances with strepogenin activity for L. casei were not active for L. bulgaricus.