SPECIES OF STREPTOMYCES 111 



bottom and numerous colonies throughout medium; surface growth granu- 

 lar; aerial mycelium gray, flecked with white. 



Tyrosinase reaction : Negative. 



Temperature: Grows well at 37.5°C. 



126. Streptomyces scabies (Thaxter) Waksman and Henrici. (Thax- 

 ter, R., Ann. Rept. Conn. Agr. Exp. Sta., 1891, 153.) 



Vegetative growth: Folded, compact, yellowish to yellow-brown; sol- 

 uble pigment brown. 



Aerial mycelium: White cottony or velvety; wavy or slightly curved 

 hyphae show a few spirals. Spores cylindrical, 0.8-1.0 by 1.2-1.5 ju. 



Synthetic agar: Growth abundant, wrinkled, raised, gray to cream- 

 colored. Aerial mycelium scarce, white to gray. 



Nutrient agar: Colonies circular, entire, smooth, becoming raised, lich- 

 noid, wrinkled, white to straw-colored, opalescent to opaque; no aerial 

 mycelium; soluble pigment deep golden brown. 



Glucose agar: Growth restricted, folded, cream-colored; aerial mycelium 

 scant, white to gray. 



Potato: Growth gray, opalescent, becoming wrinkled, black; aerial my- 

 celium scant, grayish white. Color of plug brown. 



Gelatin: Surface growth cream-colored, becoming brown. Liquefaction 

 slow; soluble pigment yellowish. 



Milk: Ring brown with greenish tinge. Coagulation; peptonization with 

 alkaline reaction. 



Starch: Hydrolysis. 



Glucose broth: Ring in form of small colonies, settling to the bottom. 



Nitrate: Reduction. 



Tyrosinase reaction : Strong. 



Temperature: Grows at 37°C. 



Antagonistic properties : Certain strains give positive effects, others nega- 

 tive. 



Habitat: Numerous strains of this organism have been isolated from 

 potato scab. 



Remarks: Streptomyces clavifer, Streptomyces spiralis, Streptomyces carno- 

 sus, Streptomyces sampsonii, and many other species or strains are closely 

 related to the type. 



127. Streptomyces tenuis (Millard and Burr) comb. nov. (Millard, 

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



Aerial mycelium: Irregularly branched. Spores cylindrical, 0.87 by 0.82 p. 

 Synthetic sucrose agar: Growth penetrates deep into substratum. Sur- 



