810 



ORDER V. ACTINOMYCETALES 



sca'bi.es. L. noun scabies scab. 



Vegetative growth: Folded, compact 

 yellowish to yellow-brown; soluble, brown 

 pigment. 



Aerial mycelium: White, cottony or vel- 

 vety; wavy or slightly curved hyphae show 

 a few spirals. Spores cylindrical, 0.8 to 1.0 

 by 1.2 to 1.5 microns. 



Gelatin stab: Cream-colored surface 

 growth, becoming brown. Slow liquefac- 

 tion. Yellowish soluble pigment. 



Agar: Circular, entire colonies, smooth, 

 becoming raised, lichenoid, wrinkled, white 

 to straw-colored, opalescent to opaque. 

 No aerial mycelium. Deep golden brown 

 soluble pigment. 



Synthetic agar : Abundant, cream-colored, 

 wrinkled, raised growth. Aerial mycelium 

 white, scarce. 



Starch agar: Thin, transparent, spreading 

 growth. 



Glucose agar: Restricted, folded, cream- 

 colored, entire growth. 



Glucose broth: Ring in form of small 

 colonies, settling to the bottom. 



Litmus milk: Brown ring with greenish 

 tinge; coagulated; peptonized with alka- 

 line reaction. 



Potato: Gray, opalescent growth, be- 

 coming black, wrinkled. Brown plug. 



Brown soluble pigment formed. 



Starch is hydrolyzed. 



Strong tyrosinase reaction. 



Nitrites produced from nitrates. 



Aerobic. 



Optimum temperature, 37° C. 



Antagonistic properties: Certain strains 

 give positive effects, others negative. 



Comments: The potato scab organism, 

 like other acid-fast organisms, can be se- 

 lectively impregnated with carbol-auramin 

 and when exposed to ultraviolet radiation 

 fluoresces bright yellow. This technic con- 

 firms Lutman's conclusion that the hyphae 

 are intercellular and grow within the mid- 

 dle lamellae (Richards, Stain Tech., 18, 

 1943, 91-94). 



Relationships to other species: Sfrepto- 

 myces clavifer, Streptoinyces spiralis, Sirepto- 

 myces carnosus, Streptoinyces sampsonii and 

 many other species or strains are closely 

 related to this organism. 



Source: Isolated from potato scab le- 

 sions. 



Habitat: Cause of potato scab; found in 

 soil. 



130. Streptoinyces tenuis (Millard and 

 Burr, 1926) Waksman, 1953. {Actinomyces 

 tenuis Millard and Burr, Ann. Appl. Biol., 

 18, 1926, 601; Waksman, in Waksman and 

 Lechevalier, Actinomycetes and Their 

 Antibiotics, Baltimore, 1953, HI.) 



te'nu.is. L. adj. tenuis slender. 



Aerial mycelium: Irregularly branched. 

 Spores cylindrical, 0.82 by 0.87 micron. 



Gelatin: Pale gray growth covered with 

 scant, white aerial mycelium. Soluble yel- 

 low pigment. Rapid liquefaction. 



Synthetic sucrose agar: Growth pene- 

 trates deep into substratum. Thin, fiat, 

 yellowish drab surface growth. Aerial my- 

 celium deep olive-buff. Soluble, pale orange- 

 yellow pigment. 



Synthetic glucose agar: Thin, flat growth 

 covered by olive-buff aerial mycelium. Sol- 

 uble green pigment. 



Potato agar: Wrinkled, grayish grow^th. 

 Aerial mycelium white to vinaceous-fawn- 

 colored. Soluble, golden brown pigment. 



Glycerol synthetic solution: White, flak}- 

 growth mostly at bottom. Aerial mycelium 

 scant, olive-buff. 



Glucose broth: Whitish surface and bot- 

 tom growth. Aerial mycelium abundant, 

 w^rinkled, olive-buff. Soluble, golden brown 

 pigment. 



Milk: Good growth covered with white 

 aerial mycelium. Coagulated, followed by 

 incomplete peptonization. 



Potato: Good growth covered with deep 

 olive-buff aerial mycelium. Soluble, gray to 

 olive to black pigment. 



Starch is hydrolyzed. 



Tyrosinase reaction: Negative. 



Nitrites not produced from nitrates. 



Source: Isolated from medium-sized, 

 ruptured potato scab. 



Habitat: Found in potatoes so far as 

 known. 



131. Streptoniyces niarginatus (Mil- 

 lard and Burr, 1926) Waksman, 1953. (Ac- 

 tinomyces marginatus Millard and Burr, 



