140 ACTINOMYCETES 



Habitat: Soil. 



Remarks: All strains show a marked power of utilizing paraffin wax as a 

 source of energy. 



12. Nocardia minima (Jensen) Waksman and Henrici. (Jensen, H., 

 Proc. Linnean Soc. N. S. Wales, 66, 1931, 365.) 



Mycelium: Filaments and rods 0.4-0.6 by 2-10 /x. In older cultures 

 mostly short rods, frequently V, Y, swollen forms, or cocci. Irregularly 

 stained with ordinary dyes, generally show bars and bands. Generally a 

 few cells from cultures are acid-fast, most are not acid-fast. Gram-positive. 



Nutrient agar: Slow growth, raised, folded, with finely myeloid margins. 

 At first colorless, after 6 to 8 weeks flesh pink or coral pink. 



Potato: Growth slow, after 6 to 8 weeks abundant, spreading, much 

 raised, finely wrinkled, coral-pink. 



Gelatin: Filiform, granulated, cream-colored growth. No liquefaction. 



Paraffin: Utilized. 



Temperature: Optimum 22°-25°C. 



Habitat: Soil. 



Remarks: Closely resembles Nocardia corallina but differs in the much 

 slower growth and the smaller size of the cells. 



13. Nocardia corallina (Bergey et al.) Waksman and Henrici. (Hef- 

 feran, M., Centrbl. Bakt. II, 11, 1904, 459; Bergey et al., Manual, 1st 

 ed., 1923, 93.) 



Mycelium: Branching rods, generally curved, 1-1.5 by 3-10 /x- In older 

 cultures generally shorter rods and cocci. Nonmotile. Not acid-fast. 

 Gram-positive. 



Nutrient agar: Round, convex, or umbonate colonies, smooth, pink, 

 shining or matte; border lighter, edge filamentous or with arborescent pro- 

 jections. Deep colonies : burrs, or lens-shaped, with arborescent projections. 

 In their very early stages colonies consist of branching filamentous rods. 

 As the colony grows, the cells in the interior break up into short rods and 

 cocci which eventually form the mass of the colony. Cells on the outside 

 remain filamentous, giving the colony a burr-like appearance, and often 

 forming long arborescent processes. Slant: filiform, convex, smooth, pink, 

 shining or matte: arborescent or with projections from undulate border. 



Gelatin: Round, convex, smooth, pink, shining colonies, edge filamentous. 

 Deep colonies: burrs. Nailhead stab: line of stab arborescent. No lique- 

 faction. 



Milk: Alkaline. Reddish pellicle. 



Nutrient broth: Usually turbid. Pink scum. 



