806 



ORDER V. ACTINOMYCETALES 



mycelium. Coagulated, followed by lique- 

 faction. 



Potato: Good, lichenoid growth, covered 

 with gray to brownish aerial mycelium 

 with white spots. The plug becomes covered 

 gray to black. 



Starch is hj'droh'zed. 



Tyrosinase reaction: Negative. 



Nitrites produced from nitrates. 



Source: Isolated from a small, unruptured 

 potato scab. 



Habitat : Found in potatoes so far as 

 known. 



121. Streptoniyces craterifer (Millard 

 and Burr, 1926) Waksman, 1953. {Actino- 

 myces craterifer Millard and Burr, Ann. 

 Appl. Biol., 13, 1926, 601; Waksman, in 

 Waksman and Lechevalier, Actinomycetes 

 and Their Antibiotics, Baltimore, 1953, 

 105.) 



cra.te'ri.fer. Gr. mas.n. crater a cup- 

 shaped hollow; L. V. fero to bear; M.L. adj. 

 craterifer cup (crater) -bearing. 



Aerial mycelium: Much branched; termi- 

 nal branches dichotomously forked. Spores 

 rectangular, 0.8 to 1.0 bj' 0.9 to 1.3 microns. 



Gelatin: Wrinkled surface growth. Aerial 

 mycelium white. No soluble pigment. Rapid 

 liquefaction. 



Agar: Colorless growth; scant, white 

 aerial mycelium. No soluble pigment. 



Synthetic agar: Lichenoid, abundant, 

 colorless growth. Aerial mj'celium mouse- 

 gray. Numerous guttation drops, which 

 leave blackish craters behind. 



Starch: Spreading, thin, colorless growth. 

 No aerial mycelium. 



Glycerol synthetic solution : Good growth 

 on surface of medium; numerous star-like 

 colonies throughout medium. Aerial mj^- 

 celium scant, white to mouse-gray. 



Glucose broth: Limited growth. Aerial 

 mycelium white to gray. 



Milk: Cream-colored surface growth. Not 

 coagulated; rapidly peptonized. 



Potato: Good, cream-colored growth. 

 Aerial m3'celium white to mouse-gray. Color 

 of plug unchanged. 



Starch is hydroh'zed. 



Tyrosinase reaction: Negative. 



Nitrites produced from nitrates. 



Only slight growth at 37.5° C. 



Source: Isolated from a large, raised, 

 smooth potato scab. 



Habitat: Found in potatoes so far as 

 known. 



122. Streptoniyces gracilis (Millard 

 and Burr, 1926) Waksman, 1953. (Actino- 

 myces gracilis Millard and Burr, Ann. Appl. 

 Biol., 13, 1926, 601; Waksman, In Waksman 

 and Lechevalier, Actinomycetes and Their 

 Antibiotics, Baltimore, 1953, 106.) 



gra'ci.lis. L. adj. gracilis slender. 



Vegetative growth: On synthetic media, 

 dark brown, producing a soluble brown 

 substance. 



Aerial mycelium: Dark olive. Spiral- 

 forming sporophores. Spores ellipsoidal or 

 spherical, 0.8 by 0.8 to 0.9 micron. 



Gelatin: Gray growth, covered with white 

 aerial mycelium. Soluble, pink to dark 

 golden brown pigment. Rapid liquefaction. 



Synthetic sucrose agar: Fern-like, pale 

 gray growth covered with scant, gray to 

 buff aerial mycelium. Soluble cream-colored 

 pigment. 



Synthetic glucose agar: Smooth, pale 

 olive-gray grow^th. Aerial mycelium abun- 

 dant, white, smooth. Soluble cream-colored 

 pigment. 



Nutrient potato agar: Vinaceous, buff to 

 dark brown or almost black growth. Aerial 

 mycelium gra}^ Soluble light golden brown 

 pigment. 



Glycerol synthetic solution: Good growth 

 on surface and throughout medium. Abun- 

 dant aerial mycelium, white to olive-buff. 



Glucose broth: Good growth on surface 

 and on bottom. Aerial mycelium abundant, 

 olive-buff. Soluble, light golden brown pig- 

 ment. 



Milk: Good surface growth. Aerial my- 

 celium white in the form of a ring and specks 

 on surface. Slowly coagulated, followed b}^ 

 rapid peptonization. 



Potato: Good, echinate growth covered 

 with abundant olive-gray to buff aerial 

 mycelium. Plug light brown. 



Starch is hydrolyzed. 



TjTOsinase reaction: Negative. 



Nitrites produced from nitrates. 



Good growth at 37.5° C. 



Comment: According to Krassilnikov, 



