FAMILY III. STREPTOMYCETACEAE 



761 



white-gray. Spores almost spherical, 1.3 

 microns in diameter, often arranged in 

 chains. 



Gelatin colonies: Circular, yellowish. 



Gelatin stab: Liquefaction. 



Agar: White aerial mj-celium. 



Ca-malate agar: Yellowish colonies; gray 

 aerial mycelium. Soluble j'ellow pigment 

 formed. 



Starch agar: Abundant growth; graj' 

 aerial mycelium. Soluble yellow pigment. 



Glucose agar: Same as for starch agar. 



Glucose broth: Coarse, flaky growth. 

 Yellow pigment. 



Litmus milk: Rapidly coagulated and 

 peptonized. 



Potato: Colorless growth; aerial mycelium 

 gray. 



Strong diastatic action. 



Esculin is hydrolyzed. 



Cellulose is decomposed. 



Nitrates show slight reduction. 



Aerobic. 



Optimum temperature, between 30° and 

 35° C. 



Antagonistic properties: Positive. 



Source: Isolated from soil. 



Habitat: Soil. 



19. Slreptoniyces rimosus Sobin et al., 

 1950. (Sobin, Finlay and Kane, U. S. Pat. 

 2,516,080, July 18, 1950.) 



ri.mo'sus. L. adj. rimosus full of cracks. 



Vegetative growth: Flat, smooth colonies 

 with irregular edge; yellow pigment. 



Aerial mycelium: Limited, ocher-colored 

 in center, colonial-buff at edge; spirals nu- 

 merous; conidia 0.6 to 0.7 by 0.8 to 1.4 mi- 

 crons, cylindrical. 



Gelatin: Aerial mycelium white. No 

 soluble yellow pigment. No liquefaction. 



Agar: Poor growth, no aerial mycelium; 

 faint yellowish pigment. 



Czapek's synthetic agar: Produces very 

 limited growth which is colorless and sub- 

 merged. No aerial mycelium and no soluble 

 pigment. 



Asparagine agar: Aerial mj-celium white 

 to pallid quaker-drab; faint yellow soluble 

 pigment. 



Starch agar: Poor, thin growth; aerial 

 mycelium limited; cinnamon-drab colonies. 



Glucose agar: Growth with dry, cracked 



surface; aerial mycelium mouse-gray; yel- 

 lowish brown pigment. 



Milk: Thick pellicle, aerial mycelium 

 grayish white; not peptonized; no change in 



ph: 



Potato: Moderate, wrinkled growth; 

 aerial mycelium white to dark; yellowish 

 brown pigment. 



Starch is weakly hj^drolyzed. 



Cellulose not decomposed. 



Nitrites actively produced from nitrates. 



Odor: Earthy. 



Antagonistic properties : Produces oxytet- 

 racycline, an amphoteric substance active 

 against various bacteria, rickettsiae and the 

 larger viruses; also produces rimocidin, an 

 antifungal agent. 



Source: Isolated from soil. Cultural char- 

 acteristics described are those of isolate No. 

 S3279. A culture has been deposited with the 

 Fermentation Division of the Northern Re- 

 gional Research Laboratory, Peoria, Il- 

 linois, permanent collection number NRRL- 

 2234. 



Habitat: Soil. 



20. Streptoniyces griseoflavus (Krain- 

 sky, 1914) Waksman and Henrici, 1948. 

 {Actinomyces griseoflavus Krainsky, Cent. f. 

 Bakt., II Abt., U, 1914, 662; Waksman and 

 Henrici, in Manual, 6th ed., 1948, 948.) 



gri.se. o.fla'vus. M.L. adj. yriseus gray; 

 L. adj. flavus yellow; M.L. adj. griseoflavus 

 grayish yellow. 



Vegetative growth: Thin, cream-colored, 

 later becoming much folded or lichenoid. 



Aerial mycelium: Powdery, white, appear- 

 ing first on drier edges of growth. Sporo- 

 phores straight, abundantly branched; no 

 curvatures and no spirals produced. 



Gelatin: Cream-colored to brownish 

 growth, covered with white aerial mycelium. 

 Slow liquefaction, with faint yellowish 

 coloration of the liquefied zone. 



Agar: Cream-colored growth, covered 

 with white aerial mycelium; no soluble pig- 

 ment. 



Synthetic agar: Reddish brown to orange 

 growth, covered with white aerial mycelium; 

 faint yellowish soluble pigment. 



Ca-malate agar: Large colonies covered 

 with yellow to greenish gray aerial my- 

 celium. 



