956 



MANUAL OF DETERMINATIVE BACTERIOLOGY 



Optimum temperature 25°C. 

 Habitat: Soil. 



54. Streptomyces melanocyclus (Mer- 

 ker) comb. twv. (M icrocuccus melanocy- 

 clus Merker, Cent. f. Bakt., II Abt., 31, 

 1911, 589; Acdtiomyces melanocyclus 

 Krainsky, Cent. f. Bakt., II Abt., 41, 

 1914, 662; Nucardia 7nelanocycla Chal- 

 mers and Christopherson, Ann. Trop. 

 Med. and Parasit., 10, 1916, 268.) From 

 Greek melas, black and cyclus, circle. 



Conidia almost spherical, 0.9 micron 

 in diameter. 



Gelatin colonies : Growth poor. 



Gelatin stab : Rapid liquefaction. 



Ca-malate agar: Colonies small, flat, 

 orange-red. Aerial mycelium black, oc- 

 curring along the edges. 



Glucose broth: Same as on Ca-malate 

 agar. 



Starch agar : Same as on Ca-malate agar. 



Glucose broth: Colorless, spherical 

 colonies. 



Litmus milk: Peptonized. 



Nitrites produced from nitrates. 



Good diastatic action. 



Cellulose is decomposed. 



Aerobic . 



Optimum temperature 25°C. 



Habitat: Soil. 



55. Streptomyces acidophilus (Jensen) 

 comb. no/'. (Actinomyces acidophilus 

 Jensen, Soil Sci., 25, 1928, 226.) From 

 Greek, acid-loving. 



Vegetative mycelium profusely 

 branched, hyphae 0.6 to 0.8 micron in 

 diameter with homogeneous protoplasm 

 and no visible septa. Aerial mycelium 

 with hyphae 1.0 to 1.2 microns in di- 

 ameter, somewhat branched, forming 

 either very few or very numerous sin- 

 istrorse spirals. Oval 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. 



Nutrient 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. 



Czapek's agar : No growth. 



Plain broth: No growth. 



Milk: No growth. 



Potato: Growth good, raised, folded. 

 No discoloration. 



Nitrites not produced from nitrates 

 except a trace in two strains. 



Diastatic. 



Weakly proteolytic. 



Inversion of sucrose : Negative. 



Distinctive character : The ability to 

 live in acid media only. 



Source : Four strains isolated from 

 three acid humus soils. 



Habitat: Acid humus soils. 



56. Streptomyces rubescens (Jarach) 



comb. nov. {Streptothri.r rubescens Javach, 

 Boll. Sez. Ital. Soc. Intern. Microb., 3, 

 1931, 43.) From Latin rubescens, be- 

 coming red. 



Gelatin: No liquefaction; limited non- 

 pigmented growth. 



Glucose agar: Large number of small 

 round colonies raised in the center and 

 growing together, as well as deep into the 

 medium; of a whitish opalescent color. 



Czapek's agar : Poor growth, becoming 

 pigmented salmon-red, edge entire. 



Milk agar medium : Rose-coral-colored, 

 thin growth with edge entire. 



Broth: Minute flakes, the liquid later 

 becoming reddish-colored. 



Milk: No coagulation and no digestion; 

 slight red coloration of milk. 



Potato plug: Reddish growth, not ex- 

 tensive; opalescent surface. 



Source : From soil. 



57. Streptomyces thermophilus (Gil- 

 bert) comb. nov. {Actinomyces thermo- 

 philus Gilbert, Ztschr. f. Hyg., 47, 1904, 

 383; not Actinomyces thermophilus 

 Berestnew, Inaug. Diss., Moskow, 1897; 



