SPECIES OF STREPTOMYCES 75 



Antagonistic properties: Some strains produce neomycin or a neomycin- 

 like substance. 



Remarks: Dark brown pigment formed in organic media. 



62. Strep tomyces netropsis Finlay and Sobin. (Finlay, A. C, and 

 Sobin, B. A., U. S. Pat. 2,586,762, 1952.) 



Vegetative growth: Growth sb'ghtly elevated, with rough surface and 

 smooth edge. Reverse brown. 



Aerial mycelium: White. Sporophores in form of whorls or terminal 

 clusters of short hyphae on tips of short hyphae. Conidia short, cylindrical, 

 0.7 by 1.3 M . 



Synthetic agar: Growth thin, pale olive-buff. Pale vinaceous fawn aerial 

 mycelium. No soluble pigment. 



Nutrient agar: Growth moderate to good, light brown; white aerial myce- 

 lium, light brown soluble pigment. 



Glucose agar: Growth good, dark brown. White aerial mycelium. Brown 

 soluble pigment. 



Potato: Growth poor, waxy, wrinkled, brown. No aerial mycelium. Dark 

 brown pigment. 



Gelatin: Moderate surface growth. White aerial mycelium. Dark brown 

 soluble pigment. No liquefaction. 



Milk: Growth poor. No peptonization. 



Starch: Growth moderate, thin; pale olive-buff reverse. White aerial 

 mycelium. No soluble pigment. Strong hydrolysis. 



Nitrate: No reduction. 



Glucose-asparagine agar: Growth moderate, wrinkled. White aerial myce- 

 lium. Soluble brown pigment. 



Calcium malate agar: Growth moderate, cream to buff. White aerial 

 mycelium. No soluble pigment. 



Antagonistic properties: Produces a basic antibiotic, netropsin. 



63. Strep tomyces verticillatus (Kriss) comb. nov. (Kriss, A., Mi- 

 crobiologia, 7, 1938, 111.) 



Vegetative growth: Colorless or slightly brownish, smooth or rough col- 

 onies. 



Aerial mycelium: Characteristic primary whorl formation of straight 

 sporophores. Spores cylindrical, oblong, 1.0-1.9 by 0.8 /x. 



Synthetic agar: Aerial mycelium well-developed, velvety, at first white, 

 later dark gray or gray-green . 



Nutrient agar: Growth brown. Soluble pigment brown. No aerial myce- 

 lium. 



Potato: Soluble pigment brown. 



