942 



MANUAL OF DETERMINATIVE BACTERIOLOGY 



Glucose agar: Brown soluble pigment 

 formed. 



Starch agar: Yellow colonies, with 

 white aerial mycelium. 



Glucose broth: Fine flakes, with small 

 spherical colonies adherent to glass. 

 Medium colored brown. 



Potato: Yellow colonies, with white 

 aerial mycelium. 



Nitrites produced from nitrates. 



Weakly diastatic. Esculin acted upon. 



Slow growth on cellulose . 



Tyrosinase formed. 



Aerobic. 



Optimum temperature 35°C. 



Habitat: Soil. 



19. Streptomyces antibioticus (Waks- 

 man and Woodruff) comb. nov. {Actino- 

 myces antibioticus Waksmau and Wood- 

 ruff, Jour. Bact., 42, 1941, 232 and 246.) 

 From Greek, antibiotic. 



Spore-bearing hyphae produced in the 

 form of straight aerial hyphae. The 

 conidiophores are arranged in clusters ; no 

 spirals formed. The conidia are nearly 

 spherical to somewhat elliptical. 



Gelatin : Dark brown growth on surface, 

 with patches of gray aerial mycellium. 

 Dark pigment produced, which gradually 

 diffuses into the unliquefied part of the 

 gelatin. Liquefaction at first very slow, 

 later becoming rapid. 



Czapek's agar: Thin, whitish growth. 

 Thin, gray aerial mycelium. 



Peptone media: Production of dark 

 pigment at early stage of growth is very 

 characteristic. Growth brownish, thin, 

 with a yellowish-gray to yellowish-green 

 aerial mycelium. 



Potato plug: Folded, brown-colored 

 growth, with a thin black ring on plug, 

 fading into a bluish tinge. No aerial 

 mycelium. 



Carrot plug: Cream-colored to faint 

 brownish growth. No aerial mycelium. 

 No pigment. 



Litmus milk : Thick, brownish ring on 

 surface of milk. Mouse-gray aerial my- 

 celium with greenish tinge ; growth be- 



comes brown, especially in drier portions 

 adhering to glass. No reaction change, 

 no coagulation of milk, no clearing; whit- 

 ish sediment at bottom of tube. Old cul- 

 tures : Heavy growth ring on surface of 

 milk, heavy precipitation on bottom; li- 

 quid brownish to black in upper portion. 



Odor: Very characteristic soil odor. 



Antagonistic properties : Has a marked 

 antagonistic effect on Gram-positive and 

 Gram-negative bacteria, much more on 

 the former than on the latter, as well as on 

 actinomycetes. It is also active against 

 fungi, which vary in degree of sensitivity. 

 Produces a specific bacteriostatic and 

 bactericidal substance known as actino- 

 mycin (Waksman and Woodruff, Jour. 

 Bact., 40, 1940, 581). 



Source : Isolated from soil on Escheri- 

 chia coZt-washed-agar plate, using living 

 cells of E. coll as the only source of avail- 

 able nuti'ients. 



Habitat: Soil. 



20. Streptomyces viridochromogenes 



(Krainsky) comb. nov. {Actinomyces vir- 

 idochromogenes Krainsky, Cent. f. Bakt., 

 II Abt., 41, 1914, 662; Waksman and 

 Curtis, Soil Science, 1, 1916, 114.) From 

 Latin, green and Greek, producing 

 color. 



Filaments with numerous open spirals, 

 3 to 5 microns in diameter, occurring as 

 side branches and terminal conidia, short 

 ovals or spheres, 1.25 to 1.5 microns. 



Gelatin stab : Cream-colored surface 

 growth, becoming greenish. Slow lique- 

 faction. 



Synthetic agar : Spreading growth, 

 cream-colored with dark center, becoming 

 dark green; reverse yellowish to light 

 cadmium. Aerial mycelium abundant, 

 spreading, white, becoming light green. 



Starch agar: Circular, spreading, yel- 

 lowish colonies. 



Glucose agar ; Abundant, spreading, 

 wrinkled, gray growth, becoming black. 



Plain agar: Abundant, restricted, gray 

 growth, with greenish tinge. 



