Formation of Tyrothricin in Submerged Cultures of Bacillus Brevis

Abstract

Tyrothricin is synthesized by B. brevis in shallow stationary cultures of complex nitrogenous media, but it is not formed, or does not accumulate, in aerated submerged cultures of such media. However, tyrothricin is formed in both submerged and stationary cultures in a synthetic medium consisting of glucose, inorganic salts and asparagine. Glycine, d-glutamic acid and other amino acids can be substituted for asparagine. The bactericidal agent is not produced in synthetic media under submerged conditions in the presence of a mixture of 19 amino acids. The failure of tyrothricin to appear in submerged cultures containing complex nitrogenous substances appears to be associated with the amino acids of the latter.