82 ACTINOMYCETES 



Starch: Growth abundant, yellowish green. Hydrolysis positive. 

 Glucose broth: Ring thin, wide, yellow; sediment flaky. 

 Nitrate: Reduction slight. 

 Temperature: Optimum 37 °C. 

 Antagonistic properties: Negative. 

 Remarks: The pigment formed is not soluble. 



75. Streptomyces fulvissimus (Jensen) Waksman and Henrici. (Jen- 

 sen, H. L., Soil Sci., 30, 1930, 66.) 



Vegetative growth: Mycelium without any special characteristics. 



Aerial mycelium: Hyphae short, straight, often trifurcated, 1.0-1.2 ju 

 broad; no spiral formation; branches of hyphae break up into conidia, 1.0- 

 1.2 by 1.2-1.5 n. 



Nutrient agar: Growth good ; vegetative mycelium raised, finely wrinkled, 

 deep red-brown; no aerial mycelium; pigment brownish yellow. 



Potato: Growth good; vegetative mycelium raised, much wrinkled, rust- 

 brown; aerial mycelium absent or traces of white; pigment gray to faint 

 lemon-yellow. 



Gelatin: Vegetative mycelium narrow, smooth, yellowish brown to red- 

 brown; no aerial mycelium; no pigment; liquef action complete in 10 to 12 

 days. 



Czapek's agar: Growth good (one strain very scant) ; vegetative mycelium 

 flat, narrow, first light golden, later deep orange to red-brown; aerial myce- 

 lium scant, sometimes almost absent, first white, later light grayish brown; 

 pigment very characteristic, bright golden to orange. 



Glycerol agar: Growth good; vegetative mycelium narrow, raised, 

 smooth, golden to dark bronze; aerial mycelium scant, in patches, white 

 to light cinnamon-brown; pigment intensely golden to orange. 



Loeffler's blood serum: Vegetative mycelium red-brown; no aerial myce- 

 lium; pigment yellowish; no liquef action. 



Starch-casein agar: Growth good; vegetative mycelium spreading, folded, 

 yellowish brown; aerial mycelium abundant, smooth, lead-gray; pigment 

 dull yellow to orange. 



Remarks: The characteristic golden pigment is formed in nearly all 

 media in which the organism grows, but becomes most typical and attains 

 its greatest brightness in synthetic agar media ; it has indicator properties, 

 turning red in strongly acid solutions. The species is easily recognized on 

 agar plates by its bronze-colored colonies, surrounded by halos of bright 

 yellow pigment. 



76. Streptomyces chrysomallus Lindenbein. (Lindenbein, W., Arch. 

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



