92 ACTINOMYCETES 



Antagonistic properties: Limited. 



Remarks : The pigment formed is not soluble. 



93. Streptomyces halstedii (Waksman and Curtis) Waksman and 

 Henrici. (Waksman, S. A., and Curtis, R. E., Soil Sci., 1, 1916, 124.) 



Aerial mycelium: Mycelium branching; hyphae with close spirals. Conidia 

 oval or rod-shaped, 1.0-1.2 by 1.2-1.8 /x. 



Synthetic agar: Growth abundant, heavy, spreading, raised, light, be- 

 coming dark, almost black. Aerial mycelium white, turning dull-gray. 



Nutrient agar: Growth restricted, wrinkled, cream-colored. 



Glucose agar: Growth spreading, colorless, wrinkled, center elevated, 

 edge lichnoid, becoming brown. 



Potato: Growth abundant, moist, wrinkled, cream-colored with green 

 tinge. 



Gelatin: Liquefaction; small, cream-colored masses in bottom of tube. 



Milk : Ring cream-colored ; coagulation ; peptonization, becoming alkaline. 



Starch: Growth abundant, glossy, brownish. Hydrolysis. 



Glucose broth : Colonies in bottom of tube small, colorless. 



Nitrate: Reduction to nitrite. 



Temperature: Optimum 37°C. 



Antagonistic properties: Strongly antagonistic; some strains show only 

 antifungal activity; some strains produce carbomycin. 



Remarks: The pigment formed is not soluble. 



94. Streptomyces fumosus (Krassilnikov) comb. nov. (Krassilnikov, 

 N. A., Actinomycetales, Akad. Nauk. USSR, Moskau, 1941, 58.) 



Aerial mycelium: Sporophores straight; spores cylindrical, 1.5-2.0 by 

 0.7/x, later round. 



Synthetic agar: Growth dark brown, pigment insoluble; aerial mycelium 

 well developed, cottony, dusty-colored, occasionally gray-white. 



Nutrient agar: Growth dark brown, aerial mycelium white; medium 

 brown-colored. 



Potato: No growth, or only faint dark gray aerial mycelium. 



Gelatin: Liquefaction medium. 



Milk: No coagulation; liquefaction slow, with production of dark brown 

 to almost black pigment. 



Starch: Hydrolysis good. 



Cellulose: No growth. 



Sucrose: Inversion weak. 



Antagonistic properties : None. 



