154 ACTINOMYCETES 



Synthetic agar: Cultures use inorganic sources of nitrogen and sugar, 

 starch, or organic acids as sources of carbon. 



Nutrient agar: Good growth. 



Gelatin: Liquefaction positive. 



Milk: Coagulation and peptonization. 



Starch: Rapid hydrolysis. 



Cellulose: No growth. 



Nitrate: No reduction. 



Sucrose: Inversion. 



Source: Soil. 



Remarks: Several subspecies listed: Nocardia chromogena, Nocardia alba 

 lactica, Nocardia diastaticus. 



34. Nocardia flavescens (Jensen) Waksman and Henrici. (Jensen, H. 

 Proc. Linnean Soc, N. S. Wales, 56, 1931, 361.) 



Mycelium: On media where a firm growth is produced, the vegetative 

 mycelium appears as long, branched, nonseptate hyphae, 0.4-0.6 ju thick. 

 In other media, as on nutrient agar and potato, septa are formed and the 

 mycelium appears in preparations as fragments of very variable size, partly 

 resembling highly branched mycobacteria. In several cases — for instance, 

 on nutrient agar at 28°-30°C, in 5- to 6-week-old cultures in glucose broth, 

 and in glucose NH 4 C1 solution — short elements assume swollen, fusiform to 

 lemon-shaped forms. The aerial mycelium consists of fairly long hyphae of 

 the same thickness as the vegetative hyphae, not very much branched, 

 without spirals, often clinging together in wisps. A differentiation into 

 spores is never visible by direct microscopic examination. Neither is this 

 the case in stained preparations; here the aerial hyphae break up into 

 fragments of variable lengths, from 1.2-1.5 up to 10-12 n, showing an ir- 

 regular, granulated staining. 



Nutrient agar: Good growth. Vegetative mycelium raised and much 

 wrinkled, first dirty cream-colored, later dark yellowish gray, of a soft, 

 moist, curd-like consistency. No aerial mycelium. No pigment. 



Glucose agar: Good growth. Vegetative mycelium superficial, wrinkled, 

 honey-yellow, of a hard and cartilaginous consistency. Aerial mycelium 

 thin, smooth, white. Yellow soluble pigment. 



Potato: Good to excellent growth. Vegetative mycelium much raised and 

 wrinkled, first cream-colored, later yellowish brown, soft and smeary. No 

 aerial mycelium. No pigment. 



Gelatin: Slow liquefaction. 



Milk: Coagulation; slowly redissolved with acid reaction. 



Starch: Hydrolysis. 



Cellulose: No decomposition. 



