SPECIES OF STREPTOMYCES 45 



Glucose agar: Growth restricted, much folded, cream-colored, with sulfur- 

 yellow tinge. 



Potato: Growth glossy, yellow to red, turning red-brown. 



Gelatin: Surface growth gray, moist, abundant; no soluble pigment. 

 Medium liquefaction. 



Milk: Surface growth faint, brownish. Coagulation and slow peptoniza- 

 tion. 



Starch: Growth spreading, pink center with colorless to gray margin. 

 Hydrolysis. 



Glucose broth; Mass on surface solid cream-colored, with pink tinge. 



Nitrate: Reduction to nitrite. 



Temperature: Optimum 37°C. 



Antagonistic properties: Limited. Some strains produce viomycin. 



14. Streptomyces virgatus (Krassilnikov) comb. nov. (Krassilnikov, 

 N. A., Actinomycetales, Akad. Nauk. USSR. Moskau, 1941, 32.) 



Vegetative growth: Colonies yellow-green to citron-yellow or pure yel- 

 low; on some media pale green. Pigment insoluble in substrate. Some strains 

 produce brown substance in protein media. 



Aerial mycelium: Weakly developed, white or pale yellow. Sporophores 

 produced in form of tufts. Oidiospores cylindrical, elongated; in some 

 strains round-oval. 



Gelatin: Liquefaction rapid. 



Milk: Coagulation and peptonization rapid. 



Starch: Hydrolysis rapid. 



Cellulose: No growth. 



Nitrate: Reduction good. 



Antagonistic properties: None. 



15. Streptomyces flaveolus (Waksman) Waksman and Henrici. Waks- 

 man, S. A., Soil Sci., 8, 1919, 134). 



Aerial mycelium: Numerous closed and open spirals on all media. Spores 

 oval to elliptical. 



Synthetic agar: Growth light sulfur-yellow turning to cadmium-yellow, 

 penetrating deep into medium. Aerial mycelium white to ash-gray. 



Nutrient agar: Growth white, glistening, wrinkled. 



Glucose agar: Growth restricted, surface folded, raised. 



Potato: Growth abundant, wrinkled, cream-colored. 



Gelatin: Abundant, yellowish, spreading surface. Liquefaction rapid. 



Milk: Ring sulfur-yellow. Coagulation and peptonization. 



Starch: Growth white, spreading. Hydrolysis. 



Glucose broth: Pellicle thin, yellow. 



