Isolation and Purification of Streptomycin

There has been considerable interest recently in the antibiotic agents streptothricin and streptomycin (l-11). These substances are antagonistic to Gram-negative bacteria as well as to Gram-positive. Streptomycin has a low toxicity (5) and shows promise for the treatment of infections whichare resistant to penicillin (4-11). In the first reports on streptomycin and streptothricin Waksman and coworkers (1, 3) indicated that they were water-soluble organic bases. Since that time little chemical information about these substances has appeared until the recent paper of Fried and Wintersteiner (12). These authors describe certain properties of streptothricin and streptomycin, including the preparation of crystalline salts of the two bases with Reinecke acid, but give no details of the preparation of streptomycin. It is the purpose of this paper to present the methods developed in our laboratory for the isolation and purification of streptomycin. Surface culture filtrates of Streptomyces griseus assaying 100 to 180 units1 of streptomycin per ml. served as the starting material for this work.2 Butyl alcohol fails to remove act,ive material from an aqueous solution over a pH range of 2 to 9, and more alkaline solutions inactivate streptomycin. Streptomycin dialyzes rapidly from the culture filtrate but such a process has proved of no great practical value. A study of adsorption methods revealed that a variety of common agents removes streptomycin from an aqueous solution. The use of carbon as described by Schatz, Bugie, and WStksman (3) proved to be satisfactory, the activity being eluted from the carbon with hydrochloric acid in 95 per cent ethanol.