CHARACTERIZATION OF STREPTOMYCES SPECIES 



79 



Figube 21. Formation of straighl sporophores by Streptomyces sp., X L500 (Courtesy of -Miss A. 

 Dietz, Dept. of Microbiology, Upjohn Co., Kalamazoo, .Mich.). 



equivalenl to the original soil isolates, as 

 determined by the methods of assessmenl 

 used. 



The prior growth of the organism in soil 

 media (sterile soil treated with a small 

 amounl of CaC( h , it' acid, and with a half 

 per cent of dried Mood) or in carbon- or ni- 

 trogen-poor media, its refrigeration or its 

 lyophilization each or all tend to prevent 



degeneration and thus preserve the original 

 characteristics of the type culture. The cul- 

 tures that have already degenerated will 

 tend to regain their original properties as a 

 result of such i real ments. 



Shinobu l L958) suggested the following 

 method for making a soil medium: Into a 

 test tube of L.5 cm diameter place 7 g dried 

 fertile soil; add L.5 ml of 1* per cent solution 



