68 ISOLATION AND CULTIVATION OF ANTAGONISTS 



Streftothrkin and Streftomycin 



For the production of streptothricin, a tryptone medium with starch 

 or glucose is used. A typical medium is given here: 



For stationary cultures, 0.25 per cent agar may be added. 



For streptomycin, certain specific organic precursors are required. 

 The precursors are present in meat extract, in corn steep, and in the 

 cells of certain microorganisms such as yeasts and actinomycetes. A typi- 

 cal medium, on a liter basis, consists of: 



For spore production, a simple synthetic medium may be used, such 

 as glucose-asparagine agar, consisting of: 



A synthetic medium has also been suggested (905a) for streptomy- 

 cin production, consisting of: 



