SUBSTANCES PRODUCED BY ACTINOMYCETES 



193 



the sulfate is 500-530 [ig/mg. One of the more recent modifications 

 (713a) of the method of isolation of streptothricin comprises the fol- 

 lowing steps: charcoal adsorption, elution with formic acid in methyl 

 alcohol-water, partial concentration in vacuo, precipitation with picric 

 acid, conversion to hydrochloride, chromatography over aluminum 

 oxide, and precipitation with methyl orange as helianthate. This 

 preparation had an activity of 830 ng/mgl., with a specific rotation 



Streftomycin 



Streptomycin is produced, in stationary and shaken cultures, in a 

 medium containing meat extract, corn steep, soy bean meal, or some 

 other suitable material. Its maximum production occurs in shaken cul- 

 tures in 2 to 3 days, and in stationary cultures in 7 to 10 days (830, 

 971), as shown in Table 34. 



TABLE 34. GROWTH OF S. GRISEUS AND PRODUCTION OF STREPTOMYCIN 



From Schatz, Bugie, and Waksman (830). 



* Weight of dry m>'celium produced by S. griseus. 



Streptomycin is also a base, like streptothricin, but differs from it in 

 cl^emical composition, antibacterial spectrum, and lower toxicity for 

 animals (830, 952). It is highly active against the gram-negative en- 

 teric group of bacteria and related organisms. A detailed discussion of 



