FAMILY III. STREPTOMYCETACEAE 



783 



Habitat: Found in wheat soil so far as 

 known. 



66. Streptoniyces circulatus (Krassil- 

 nikov, 1941) Waksman, 1953. {Actinomyces 

 circulatus Krassilnikov, Guide to the Acti- 

 nomycetes, Izd. Akad. Nauk, U.S.S.R., 

 Moskau, 1941, 60; Waksman, in Waksman 

 and Lechevalier, Actinomycetes and Their 

 Antibiotics, Baltimore, 1953, 76.) 



cir.cu.la'tus. L. part. adj. circulatus 

 curled. 



Vegetative growth: Better on synthetic 

 media than on organic media. 



Aerial mycelium: Spiral-producing sporo- 

 phores formed in whorls. Spores cylindrical, 

 oblong, 0.7 by 1.5 microns, some rounding 

 up as culture ages. 



Gelatin: Weak liquefaction. 



Agar: Poor growth. No aerial mycelium. 



Synthetic agar: Good growth, producing 

 abundant, white aerial mycelium. 



Milk: Not coagulated; slowly peptonized. 



Sucrose not inverted. 



Starch is weakly hydrolyzed. 



No growth on cellulose. 



Nitrites weaklj^ produced from nitrates. 



Antagonistic properties : Limited. 



Source: Isolated from soil. 



Habitat: Soil. 



67. Streptomyces rubrireticuli Waks- 

 man and Henrici, 1948. {Actinomyces reticu- 

 lus-ruber Waksman, Soil Sci., 8, 1919, 146; 

 Actinomyces reticulus Bergey et al.. Manual, 

 2nd ed., 1925, 373; Waksman and Henrici, 

 in Manual, 6th ed., 1948, 945.) 



ru.bri.re.ti'cu.li. L. adj. ruber red; L. 

 noun reticulum a small net; M.L. gen. noun 

 rubrireticxdi of a small red net. 



Aerial mycelium: Branching filaments 

 with both primary and secondary whorl 

 formation. Spirals formed on glucose agar. 

 Conidia ellipsoidal. 



Gelatin stab: Surface growth yellowish 

 red to dragon -pink. Liquefaction. 



Agar: Red growth, with yellowish margin 

 becoming red. 



Synthetic agar: Abundant, spreading 

 growth, usually pink. Aerial mycelium 

 thin, rose to pink. 



Starch agar: White growth with red tinge. 



Glucose agar: Abundant, spreading, 

 rose -red, entire growth. 



Glucose broth: Thin, flaky sediment. 



Litmus milk: Abundant, red pellicle; 

 coagulated; peptonized. Reaction un- 

 changed. 



Potato: Cream-colored growth, later pink 

 to dark red. 



Soluble dark brown pigment formed. 



Starch is hydrolyzed. 



Good growth on cellulose. 



Nitrites produced from nitrates. 



Aerobic. 



Optimum temperature, 37° C. 



Antagonistic properties: Certain strains 

 of this organism produce an antibiotic, 

 designated as streptin. 



Source: Isolated from a New Jersey 

 orchard and from California upland soils. 



Habitat: Soil. 



68. Streptomyces flavus (Krainsky, 

 1914) Waksman and Henrici, 1948. {Actino- 

 myces flavus Krainsky, Cent. f. Bakt., II 

 Abt., 41, 1914, 662; also see Waksman and 

 Curtis, Soil Sci., 1, 1916, 118; not Actino- 

 myces flavus Sanfelice, Cent. f. Bakt., I 

 Abt., Orig., 36, 1905, 359; Waksman and 

 Henrici, in Manual, 6th ed., 1948, 945.) 



fla'vus. L. a,d]. flavus yellow. 



Aerial mycelium: Coarse filaments with 

 branching hyphae. Conidia formed by bud- 

 ding and breaking up of hyphae into ellip- 

 soidal forms. 



Gelatin stab: Small, yellowish masses on 

 surface of liquefied medium. 



Agar: Gray, spreading, folded growth. 



Synthetic agar: Circular, yellow or sulfur- 

 yellow colonies. Aerial mycelium straw- 

 yellow. 



Starch agar: Spreading, cream-colored 

 growth, with pink tinge. 



Glucose agar: Restricted, raised, folded, 

 sulfur-yellow growth, center shading to 

 brown. 



Glucose broth: Small, white colonies in 

 bottom of tube. 



Litmus milk: Coagulated; peptonized, 

 becoming distinctly alkaline. 



Potato: Elevated, much wrinkled, green- 

 ish olive growth. 



Soluble brown pigment formed. 



Starch is hydrolyzed. 



