46 ACTINOMYCETES 



Nitrate: Reduction to nitrite. 



Antagonistic properties: Some strains produce actinomycin. 



Remarks: Culture produces soluble empire-yellow pigment. 



16. Streptomyces parvus (Krainsky) Waksman and Henrici. (Krain- 

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



Vegetative growth : Golden yellow to brick-red, depending on composition 

 of medium. 



Aerial mycelium: Poorly developed, rose-white. Sporophores produce 

 spirals. Spores spherical to oval, 0.9-1.3 by 1.2-1.8 ju. 



Glucose agar: Colonies small, yellow, with aerial mycelium light yellow. 



Gelatin: Colonies yellow. Liquefaction medium. 



Milk: Coagulation and peptonization rapid. 



Starch: Diastatic action good. 



Cellulose: Growth good. 



Glucose broth: Hemispherical colonies in bottom of tube. 



Nitrate: Reduction slight. 



Calcium malate agar: Same as on glucose agar. 



Antagonistic properties: Produces actinomycin. 



17. Streptomyces xanthophaeus Lindenbein (Lindenbein, W., Arch. 

 Mikrobiol., 17, 1952, 361-383.) 



Synthetic agar: Growth good, crumb-like, smooth, brownish. Aerial 

 mycelium cottony white, later grayish or even reddish gray. Soluble pig- 

 ment light brown, later yellow-brown. 



Nutrient agar: Growth good, diffuse, smooth, light brown reverse. Aerial 

 mycelium powdery ash-gray to white. Soluble pigment yellow to yellow- 

 brown. 



Glucose agar : Growth good, diffusive, colorless, with light yellow reverse. 

 Aerial mycelium powdery, seldom velvety, abundant, light brown. Soluble 

 pigment yellow. 



Potato: Growth good, lichnoid. Aerial mycelium powdery gray. No sol- 

 uble pigment. 



Gelatin: Growth good, leathery, brown. Aerial mycelium velvety, ash- 

 gray. Soluble pigment yellow-brown. Liquefaction strong. 



Milk: Growth good, lichnoid. Aerial mycelium gray to violet. Soluble 

 pigment dark brown. Peptonization strong. 



Starch: Growth good, lichnoid. Aerial mycelium velvety, violet-gray. 

 Hydrolysis rapid. 



Cellulose: No growth. 



Glucose broth: Surface growth good, colorless, later producing heavy 

 sediment. Abundant flocculent particles. Aerial mycelium cottony, grayish 



