Observations on Streptomyces griseus

Abstract
Using a basal medium of glucose and inorganic salts, a number of compounds were investigated as N sources for growth and streptomycin production by S. griseus in shake flasks. Out of 5 inorganic N sources, 0.4% (NH HPO4 gave best yields (150 micrograms per ml.), whereas nitrate was not utilizable. Addition of 0.1% corn steep solids to the glucose (NH4)2HPO4 medium doubled the potency. This stimulatory effect was not obtained when single amino acids were substituted for corn steep solids. Of 33 organic compounds used in place of (NHJgHPO,, only DL-alpha-alanine, beta-alanine, L-histidine HC1, glycine, L-proline, and L-arginine HC1 gave yields above 100 micrograms per ml. By far the best streptomycin production was obtained with L-proline, which gave potencies of 800 micrograms per ml. of medium.