SPECIES OF STREPTOMYCES 65 



est in freshly isolated cultures. Property lost on cultivation; activity upon 

 gram-negative bacteria is lost at first, then upon gram-negative rods; 

 cocci remain most sensitive. 



Remarks: Highly proteolytic and lipolytic. Grows best on complex or- 

 ganic media, at slightly acid reaction of pH 6.0-6.6. 



46. Streptomyces antibioticus (Waksman and Woodruff) Waksman 

 and Henrici. (Waksman, S. A., and Woodruff, H. B., J. Bacterid., #?, 

 1941, 232, 246.) 



Aerial mycelium: Spore-bearing hyphae produced in the form of straight 

 aerial hyphae. Conidiophores arranged in clusters; no spirals formed. Con- 

 idia nearly spherical to somewhat elliptical. 



Synthetic agar: Growth thin, whitish. Aerial mycelium thin, gray. 



Nutrient agar: Production of dark pigment at early stage of growth is 

 very characteristic. Growth brownish, thin, with yellowish gray to yellow- 

 ish green aerial mycelium. 



Potato: Growth folded, brown, with thin black ring on plug, fading into 

 a bluish tinge. No aerial mycelium. 



Carrot: Growth cream-colored to faint brownish. No aerial mycelium. 

 No pigment. 



Gelatin: Surface growth dark brown; patches of gray aerial mycelium. 

 Dark pigment produced, which gradually diffuses into the unliquefied part 

 of the gelatin. Liquefaction at first very slow, later becoming rapid. 



Milk: Surface ring thick, brownish. Aerial mycelium mouse-gray with 

 greenish tinge; growth becomes brown, especially in dried portions adhering 

 to glass. No reaction change, no coagulation of milk, no clearing; whitish 

 sediment at bottom of tube. Old cultures: Heavy growth ring on surface of 

 milk, heavy precipitation on bottom; liquid brownish to black in upper 

 portion. 



Odor: Very characteristic of soil. 



Antagonistic properties: Has a marked antagonistic effect on gram-posi- 

 tive 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 actinomycin, a specific bacteriostatic 

 and bactericidal substance. 



Source: Isolated from soil on Escherichia coli- washed agar plate, using 

 living cells of E. coli as the only source of available nutrients. 



47. Streptomyces griseocarneus Grundy, Whitman, Hanes, and Syl- 

 vester. (Grundy, W. E., et al., Antibiotics & Chemotherapy, 1, 1951, 309- 

 317.) 



Vegetative growth: Good with monopodial branching. 



Aerial mycelium: Two types. On some media, powdery, suggestive of 



