108 ACTINOMYCETES 



Aerial mycelium: Well-developed, cottony, dark gray to dark olive; 

 sporophores straight, forming few spirals, spores oval-shaped, 0.6-0.8 by 

 0.85 m. 



Synthetic agar: Growth abundant, smooth. Aerial mycelium, covering 

 the whole surface, gray to olive-buff. Soluble pigment faint yellowish. 



Nutrient agar: Growth good, colorless, covered with white, smooth aerial 

 mycelium. Soluble pigment brownish. 



Glucose agar: Growth good, lichnoid, gray to brown. Aerial mycelium 

 abundant, white to olive-buff. Soluble pigment goldent brown. 



Potato : Growth heavy, wrinkled, covered with abundant white to green 

 to olive-buff aerial mycelium. Soluble pigment brownish to black. 



Gelatin: Surface growth gray, covered with white aerial mycelium. Lique- 

 faction rapid. Soluble pigment brownish. 



Milk: Surface growth good, covered with ring of white aerial mycelium. 

 Coagulation, followed by rapid digestion. 



Starch: Growth cream-colored. Aerial mycelium patchy, white. Hydrol- 

 ysis. 



Glucose broth: Growth on surface and in liquid good. Aerial mycelium 

 abundant, olive-buff. Soluble pigment light golden brown. 



Nitrate: Reduction. 



Glycerol synthetic solution: Growth flaky, white. Aerial mycelium abun- 

 dant, olive-buff. Soluble pigment greenish. 



Temperature: Grows well at 37.5°C. 



Habitat: Scabby potatoes. 



Remarks : According to Krassilnikov, Streptomyces flavus, Streptomyces 

 marginatus, Streptomyces praefecundus, Streptomyces tenuis, and Strepto- 

 myces loidensis represent merely strains of this species. 



122. Streptomyces praefecundus (Millard and Burr) comb. nov. (Mil- 

 lard, W. A., and Burr, S., Ann. Appl. Biol., IS, 1926, 580.) 



Aerial mycelium: Spores oval-shaped, 0.8 by 0.85 /x. 



Synthetic sucrose agar: Growth good, cream-colored, covered with abun- 

 dant, cottony, olive-buff aerial mycelium. Soluble pigment cream-colored. 



Synthetic glucose agar: Growth pale olive-gray, covered with abundant, 

 smooth, olive-buff aerial mycelium. Soluble pigment light golden to buff. 



Nutrient potato agar: Growth lichnoid, gray. Aerial mycelium smooth, 

 white to yellowish. Soluble pigment golden brown. 



Potato: Growth good, wrinkled, covered with abundant white to yellow- 

 ish to olive-buff aerial mycelium Soluble pigment gray to brown. 



Gelatin: Good surface growth, covered with white aerial mycelium. Light 

 pink to dark golden brown soluble pigment. Liquefaction rapid. 



