SPECIES OF STREPTOMYCES 97 



Nutrient peptone agar: Vegetative mycelium shiny cream-colored; aerial 

 mycelium moderate, pebbly, white. No diffusible pigment. 



Potato-glucose agar: Aerial mycelium abundant, pebbly, neutral gray. 

 Diffusible pigment faint, brown. 



Yeast-extract agar: Aerial mycelium abundant, pebbly, neutral gray. No 

 diffusible pigment. 



Antagonistic properties: Produces an antifungal agent, helixin. 



102. Streptomyces fradiae (Waksman and Curtis) Waksman and 

 Henrici. (Waksman, S. A., and Curtis, R. E., Soil Sci., 1, 1916, 99- 

 134.) 



Aerial mycelium: Filaments and hyphae straight, branching; no spirals. 

 Spores rod- or oval-shaped, 0.5 by 0.7-1.25 ju. 



Synthetic agar: Growth smooth, spreading, colorless. Aerial mycelium 

 thick, cottony mass covering surface, seashell-pink. 



Nutrient agar: Growth restricted yellowish, becoming orange-yellow; no 

 soluble pigment. 



Glucose agar: Growth restricted, glossy, buff-colored, lichnoid margin. 



Potato: Growth restricted, orange-colored. 



Gelatin: Growth dense, cream-colored to brownish. 



Milk: Ring faint, cream-colored; coagulation and peptonization. 



Starch: Growth spreading, colorless. Hydrolysis positive. 



Glucose broth: Ring dense, narrow, orange-colored; sediment abundant, 

 flaky, colorless. 



Nitrate: No reduction. 



Temperature: Optimum 25°C. 



Antagonistic properties: Highly antagonistic. Produces an antibacterial 

 agent, neomycin, and an antifungal agent, fradicin. 



103. Streptomyces albosporeus (Krainsky) Waksman and Henrici. 

 (Krainsky, A., Centrbl. Bakt. II, 41, 1914, 639-688.) 



Aerial mycelium: Hyphae straight, branching, with occasional spirals. 

 Spores spherical or oval, 0.8-1.2 by 1.0-1.8 ju. 



Synthetic agar: Growth spreading, colorless, with pink center, becoming 

 brownish. Aerial mycelium white, covering the whole surface. No soluble 

 pigment. 



Nutrient agar: Colonies minute, cream-colored. 



Glucose agar: Growth spreading, wrinkled, radiate, entire, red. 



Potato: Growth thin, spreading, wrinkled, gray, becoming brown with 

 greenish tinge. 



