Starch agar: Same as on Ca-malate agar. Glucose broth: Colorless, spherical colonies. Litmus milk: Peptonized. Sucrose is inverted. Starch is actively hydrolyzed. Cellulose is decomposed. Nitrites produced from nitrates. Aerobic. Optimum temperature, 25° C. Antagonistic properties: Strong effect upon various bacteria; some strains show no activity. Source: Isolated from soil. Habitat: Soil. 111. Streptomyces acidophilus (Jen- sen, 1928) Waksman and Henrici, 1948. (Actinomyces acidophilus Jensen, Soil Sci., 25, 1928, 226; Waksman and Henrici, in Manual, 6th ed., 1948, 956.) a.ci.do'phi.lus. L. adj. acidus sour; M.L. noun acidum an acid; Gr. adj. philus loving; M.L. adj. acidophilus acid-loving. Vegetative growth: Mycelium profusely branched, hyphae 0.6 to 0.8 micron in diameter with homogeneous protoplasm and no visible septa. Aerial mycelium: Hyphae 1.0 to 1.2 mi- crons in diameter, somewhat branched, forming either very few or very numerous sinistrorse spirals. Ellipsoidal conidia 1.0 to 1.2 by 1.2 to 1.5 microns. Gelatin: After 10 days, growth very scant, thin, colorless, semi-transparent. Slow liquefaction. Agar: No growth. Synthetic agar: No growth. Glucose agar: Good growth at 25° C. Substratum mycelium raised, somewhat wrinkled, colorless in young cultures. Aerial mycelium thin, white at first, later gray or yellowish brown. Starch agar: Good growth at 25° C. Substratum mycelium flat, smooth, color- less. Aerial mycelium abundant, smooth, white. Broth: No growth. Milk: No growth. Potato: Growth good, raised, folded. No discoloration. Sucrose not inverted. Diastatic. Weakly proteolytic. Nitrites not produced from nitrates except a trace in two strains. Antagonistic properties: Strongly posi- tive. Distinctive character: Ability to live in acid media only. Source: Four strains were isolated from three acid humus soils. Habitat: Found in acid humus soils. 112. Streptomyces rubesceiis (Jarach, 1931) Waksman and Henrici, 1948. (Strepto- thrix rubescens Jarach, Boll. Sez. Ital. Soc. Intern. Microb., 3, 1931, 43; Waksman and Henrici, in Manual, 6th ed., 1948, 956.) ru.bes'cens. L. part. adj. rubescens be- coming red. Original description supplemented by material taken from Umezawa, Tazaki and Fukuyama (Jour. Antibiotics (Japanese), 5, 1952,469). Aerial mycelium: Powdery, white. Micro- scopically, aerial mycelium short, curved, well branched, bearing spherical or ellipsoi- dal conidia in chains. No spirals. Gelatin: Coral -pink surface growth. No liquefaction and no pigmentation of me- dium. Agar: Submerged mycelium at first white, changing to salmon -pink after about 10 days' incubation. No soluble pigment. Re- verse of growth changes to salmon-pink. Synthetic agar: Same as on plain agar. Glucose agar: Large number of small round colonies raised in the center and growing together as well as deep into the medium; whitish opalescent color. Milk agar medium: Rose-coral-colored, thin growth with edge entire. Loeffler's coagulated serum: Same as on plain agar. No hydrolysis. Blood agar: After 10 daj^s' incubation, mycelium becomes salmon-pink and bears powdery white aerial mycelium. No soluble pigment. No hemolysis. Broth: Minute flakes, the liquid later be- coming reddish colored. Glucose broth: Surface growth with white powdery aerial mycelium becomes salmon- pink or coral-pink. The liquid later becomes coral-red. Milk; Coral -pink growth; aerial mycelium
