Formation of Tyrothricin in Submerged Cultures of Bacillus Brevis.

Since the isolation of tyrothricin from cultures of Bacillus brevis (Dubos, 1939), numerous papers have appeared dealing with the chemical and biological properties of this bactericidal agent and its components, gramicidin and tyrocidine (Hotchkiss and Dubos, 1940; Dubos and Hotchkiss, 1941; Tishler, Stokes, Trenner and Conn, 1941; Christensen, Edwards and Piersma, 1941; Lipmann, Hotchkiss and Dubos, 1941; Heilman and Herrell, 1941; Henle and Zittle, 1941; Little, Dubos and Hotchkiss, 1941; Robinson and Molitor, 1942). However, little is known of the physiology of the bacillus from which the bactericidal agent is obtained. The present investigation is concerned with the relation of the nitrogen nutrition of B. brevis to tyrothricin formation in stationary and submerged cultures. A method suitable for large scale production of tyrothricin in submerged cultures is described.