Abt., 41, 1914, 662; also see Waksman and Curtis, Soil Sci., 1, 1916, 99; not Actinomyces citreus Gasperini, Cent. f. Bakt., 15, 1894, 684; Waksman and Henrici, in Manual, 6th ed., 1948, 946.) cit're.us. L. adj. citreus of the citrus tree; M.L. adj. citreus lemon-yellow. Aerial mycelium: Filaments with long, narrow open spirals. Conidia spherical to ellipsoidal, 1.2 to 1.5 by 1.2 to 1.8 microns. Gelatin stab: Yellowish, restricted sur- face growth. Liquefaction in 35 days. Agar: Restricted, cream-colored growth. Synthetic agar: Abundant, spreading, raised, wrinkled, citron-yellow growth. Aerial mycelium covering surface, citron- yellow. Starch agar: Abundant, yellowish green growth. Glucose agar: Extensive, glossy, olive- yellow, entire growth; center elevated. Glucose broth: Thin, wide, yellow ring; flaky sediment. Litmus milk: Cream-colored surface growth; coagulated; peptonized, becoming alkaline. Potato: Yellowish growth, aerial my- celium white. The pigment formed is not soluble. Starch is hydrolyzed. Nitrites produced in trace amounts from nitrates. Aerobic. Optimum temperature, 37° C. Antagonistic properties: Negative. Source: Isolated from soil. Habitat: Soil. 77. Streptoinyces fulvissimus (Jensen, 1930) Waksman and Henrici, 1948. (Ac- tinomyces fulvissitnus Jensen, Soil Sci., SO, 1930, 66; Waksman and Henrici, in Manual, 6th ed., 1948, 946.) ful.vis'si.mus. L. sup. adj. Jxdvissimus very yellow. Vegetative growth: Mycelium without any special characteristics. Aerial mycelium: Hyphae short, straight, often trifurcated, 1.0 to 1.2 microns broad; no spiral formation; branches of hyphae break up into conidia, 1.0 to 1.2 by 1.2 to 1.5 microns. Gelatin: Vegetative mycelium narrow. smooth, yellowish brown to red-brown; no aerial mycelium; no pigment; gelatin completely liquefied in 10 to 12 days. Agar: Good growth; vegetative mycelium raised, finely wrinkled, deep red-brown; no aerial mycelium; brownish yellow pigment. Synthetic agar: Good growth (one strain very scant), vegetative mycelium flat, narrow, first light golden, later deep orange to red-brown; aerial mycelium scant, some- times almost absent, first white, later light grayish brown; pigment very characteristic, bright golden to orange. Glycerol agar: Good growth; vegetative mycelium narrow, raised, smooth, golden to dark bronze; aerial mycelium scant, in patches, white to light cinnamon-brown; pigment intensely golden to orange. Starch-casein agar: Good growth; vegeta- tive mycelium spreading, folded, yellowish brown; aerial mycelium abundant, smooth, lead-gray; pigment dull yellow to orange. Potato: Good growth; vegetative my- celium raised, much wrinkled, rust-brown; aerial mycelium absent or traces of white; pigment gray to faint lemon-yellow. LoefBer's blood serum: Vegetative my- celium red-brown; no aerial mycelium; yellowish pigment; no liquefaction. Distinctive characters: The characteristic golden pigment is formed in nearly all media in which the organism grows, but it becomes most typical and attains its greatest bright- ness in synthetic agar media; it has indi- cator properties, turning red in strongly acid solutions. The species is easily recog- nized on agar plates by its bronze-colored colonies surrounded by haloes of bright yellow pigment. Source: Very common in Danish soils. Habitat: Soil. 78. Streptomyces chrysomallus Lind- enbein, 1952. {Streptomyces chrysomallus Brockmann, Grubhofer, Kass and Kalbe (nomen nudum), Chem. Ber., 84, 1951, 260; Lindenbein, Arch. f. Mikrobiol., 17, 1952, 369.) chry.so'mal.lus. Gr. adj. chrysomallus with golden wool. Vegetative growth: Soft on all media. Long, branched hyphae with numerous staining granules.
