SPECIES OF STREPTOMYCES 43 



Synthetic agar: Growth rough, off-white with reverse purple-red; soluble 

 blue-red pigment upon extended incubation. 



Nutrient agar: Growth rough, dry, off-white; reverse blue-red; no soluble 

 pigment. Several strains produce concentric growth rings. 



Glucose agar: Growth rough, dry, off-white; reverse dark red-blue; red- 

 blue soluble pigment only on extended incubation. 



Potato: Growth rough, slightly moist, off-white. No soluble pigment. 



Gelatin: Growth sparse, tan- white; no soluble pigment. Ready lique- 

 faction. 



Starch: Growth rough, dry, elevated, spreading, off-white. Moderate 

 hydrolysis. 



Temperature: Optimum 22°-28°C. 



Antagonistic properties: Produces vinactin, an antibiotic similar in many 

 respects to viomycin. 



Remarks: Soluble red-blue pigment produced in certain media, particu- 

 larly in glucose-peptone broth by shake culture. 



10. Streptomyces violaceus (Gasperini emend. Krassilnikov) comb, 

 nov. (Gasperini, D., Centrbl. Bakt., 15, 1894, 684; Krassilnikov, N. A., 

 Actinomycetales, Akad. Nauk. USSR, Moskau, 1941, 15.) 



Vegetative growth: Well-developed, nonseptated; readily breaks up in 

 old cultures. Colonies lichnoid, at first red becoming dark blue, finally 

 purple-violet. Some cultures produce fat droplets in the colony, pigmented 

 red or purple. 



Aerial mycelium: Produced poorly or not at all; some substrates, like 

 cellulose, paraffin, or fats favor its formation. Aerial hyphae long, straight, 

 branching seldom, and also short-branched. Sporophores forming open 

 spirals, sinistrorse curvatures. Spores spherical and oval. 



Synthetic agar: Pigments dissolved into medium, which becomes purple- 

 violet to dark violet. 



Gelatin: Liquefaction slow. 



Milk: No coagulation; peptonization slow. 



Starch: Hydrolysis weak. 



Cellulose: Growth weak or none. 



Nitrate: No reduction; few strains form nitrite. 



Sucrose: Inversion rapid. 



Temperature: Optimum 25-30°C. 



Antagonistic properties: Exerts strong antagonistic effect upon various 

 bacteria. 



11. Streptomyces verne (Waksman and Curtis) Waksman and Hen- 

 rici. (Waksman, S. A., and Curtis, R. E., Soil Sci., 1, 1916, 120.) 



