Carrot plug: Cream-colored to faint brownish growth. No aerial mycelium. No pigment. 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 actinomj'cetes. It is also active against fungi, which vary in degree of sensitivity. Produces actinomycin, a specific bacterio- static and bactericidal substance (Waks- man and Woodruff, Jour. Bact., J^0, 1940, 581). Source: Isolated from soil on Escherichia coZi-washed-agar plate, using living cells of E. coli as the only source of available nu- trients. Habitat: Soil. 49. Streptomyces griseocarneus Bene- dict et al., 1950. (Streptomyces griseo-carneus (sic) Benedict, Stodola, Shotwell, Borud and Lindenfelser, Science, 112, 1950, 77; also see Benedict, Lindenfelser, Stodola and Traufler, Jour. Bact., 62, 1951, 487; and Grund}', Whitman, Hanes and Sylvester, Antibiotics and Chemotherapj', 1, 1951, 309.) gri..se.o.car'ne.us. M.L. adj. griseus gray; L. adj. carneus pertaining to flesh, flesh-colored; M.L. adj. griseocarneus gray- ish flesh-colored. Vegetative growth: Good, with mono- podial branching. Aerial mj-celium: Two types: On some media, powdery, suggestive of sporulation, but no spores are produced; this type of mycelium usually becomes gray with con- tinued incubation. On other media, the aerial mycelium forms a rather fluffy, white mat; it turns slightly pink when sporulation occurs. No spirals have been observed. None of the common media will induce sporula- tion. It occurs best after 10 to 14 days' incubation on a carbon-free salt agar to which 0.5 per cent soluble starch has been added. Inositol and mannose will also sup- port sporulation, but they are not as satis- factory carbon sources for this purpose as starch. The only other medium on which spores are found is nitrogen-free synthetic agar to which 0.2 per cent glycine or aspara- gine is added. The spores are coccoid to ellipsoidal, 0.7 to 1.1 bj' 1.1 to 1.6 microns. Gelatin: Cream-colored to brown growth. Rapid liquefaction. Soluble dark brown pigment. Agar: Moderate, cream-colored growth. No aerial mycelium. Soluble light yellow- brown pigment. Synthetic agar: Sparse, white growth. Aerial mycelium white. No soluble pigment. No sporulation. Glucose asparagine agar: Moderate growth. Aerial mycelium powdery white. No pigment. No sporulation. Ca-malate agar: Moderate, white growth. Aerial mycelium white. No soluble pigment. No sporulation. Oatmeal agar: Luxuriant, brown growth. Aerial mycelium abundant, fluffy, white. No soluble pigment. No sporulation. Milk: Dark brown to black growth. Solu- ble brown pigment. Not coagulated; rapidly peptonized. Potato: Lu.xuriant, spreading, cream- colored growth. Aerial mycelium gray. Soluble light brown pigment turning dark brown after 30 days' incubation. Starch is hydrolyzed. Glucose, dextrin, starch, glycerol, cal- cium malate and sodium succinate are rapidly utilized as carbon sources. Mannose, maltose, inositol and sodium acetate are assimilated slowly. Xylose, galactose, sor- bose, sucrose, cellobiose, melibiose, lac- tose, mannitol, sorbitol, sodium citrate and potassium sodium tartrate are not utilized. (NH4)2HP04 , urea, asparagine, glycine and arginine are nitrogen sources which support moderate to rapid growth. Sodium nitrate supports slow growth. Tryptophane, tyrosine and methionine are not satisfac- tory nitrogen sources. Nitrites not produced from nitrates. Antagonistic properties: Produces hy- droxystreptomycin . Source: Simultaneously isolated from Japanese soil by Benedict and from soil from one of the gardens of Abbott Labs., North Chicago, Illinois. Habitat: Soil.
