SPECIES OF NOCARDIA 147 



Vegetative growth: On solid media, hyphae break up into rod-shaped 

 cells, 12-25 by 0.6-0.7m, up to 50 in length. Cells straight or slightly 

 curved, branching, gram-positive. 



Aerial mycelium: None observed, except surface layer of sporophores, 

 which produce a velvety appearance. Multiplication by fission, seldom by 

 budding. 



Nutrient agar: Good growth; smooth, shiny colonies. 



Gelatin: No liquefaction. 



Milk: No change. 



Starch: Hydolysis. 



Cellulose: No growth. 



Nutrient broth: Poor growth; produces faint turbidity, which settles 

 on bottom and leaves a surface ring. No true mycelium produced. Cells rod- 

 shaped 5-10 n, seldom 15-20 p. 



Nitrate: No reduction. 



Sucrose: Inversion. 



Source: Soil. 



Remarks: Uses glycerol well, but not paraffin. Uses nitrate as source of 

 nitrogen. 



22. Nocardia flava (Krassilnikov) Waksman and Henrici. (Krassilni- 

 kov, N. A., Bull. Acad. Sci. USSR, No. 1, 1938, 139.) 



Mycelium: Cells at first filamentous, 0.7-0.8 m in diameter; after 2-3 

 days broken into long rods and then into cocci 0.7/* in diameter. No 

 spores, some strains form chlamydospores. Cell multiplication by fission, 

 cross-wall formation, rarely by budding. Cells gram-positive; not acid-fast. 



Synthetic agar: Bright yellow or gold-colored colonies. 



Nutrient agar: Pigment bright yellow or gold color on synthetic media, 

 dirty yellow on meat-peptone media. Pigment not soluble in medium. 

 Surface of colony somewhat shiny or rough and folded, of a dough-like 

 consistency. 



Gelatin: No liquefaction. 



Milk: No peptonization or coagulation. 



Starch: Hydrolysis. 



Sucrose: Weak inversion. 



Meat peptone: Dirty yellow pigmentation. 



Habitat: Soil, not common. 



Remarks: No growth on paraffin or wax; weak growth on fat. 



23. Nocardia viridis (Krassilnikov) Waksman and Henrici. (Kras- 

 silnikov, N. A., Bull Acad. Sci. USSR, No. 1, 1938, 139.) 



