142 ACTINOMYCETES 



15. Nocardia salmonicolor (den Dooren de Jong) Waksman and 

 Henrici. (den Dooren de Jong, Centrbl. Bakt. II, 71, 1927, 216.) 



Mycelium: On glucose-asparagine agar after 18 to 24 hours, long branch- 

 ing rods are formed, 1.0-1.3 ju in thickness, with small refractive granules 

 of aerial mycelium, sometimes stretching into quite long filaments; after 

 2-3 days, small definite mycelia are present, and after 5-6 days these have 

 largely divided into short rods and cocci; the colonies have the same burr- 

 like appearance as those of Nocardia corallina. Many cells at the edge of 

 the colonies show, after 3-4 days, club- or pear-shaped swellings, up to 

 2.5-3.0 ju in width; after 5-6 days, many of these swollen cells germinate 

 with the formation of two more slender sprouts. Erikson added the follow- 

 ing characteristics. Rich salmon-pink to yellow-pigmented soft growth on 

 nutrient agar. Fair to good growth on simple media. A few short, undivided 

 aerial hyphae appear on some media, which may actually form a thin 

 white frosting over the pink growth. Acid-fastness is found among the earlier 

 stages of growth, especially in some of the strains and on some media. 



Glucose-nutrient agar: Excellent growth, spreading, flat, dense, edges 

 lobate, surface folded, glistening, yellow, gradually changing to deep 

 orange-red. 



Potato: Good growth, raised, warty, crumbly, glistening, at first buff, 

 changing to orange and finally to almost blood-red. 



Gelatin: At 20-22°C, scant arborescent growth in stab; small, wrinkled, 

 orange surface colony. No liquefaction. 



Milk: Good growth; pellicle of small cream-colored granules after 2 

 days, later a thick orange sediment. Not coagulated, but appears slightly 

 cleared after 5 weeks, the reaction becoming alkaline. 



Starch: No hydrolysis. 



Nutrient broth : Fair growth ; thin pellicle and granular sediment, at first 

 cream-colored, later red; broth clear at first, slightly turbid after 3 weeks. 



Nitrate: Reduction to nitrite. Nitrate, ammonium salts, asparagine, 

 and peptone are utilized almost equally well with glucose as source of 

 carbon, although the growth is most rapid with peptone. 



Sucrose: No inversion, although readily utilized with sodium nitrate as 

 a source of nitrogen. 



Glucose-asparagine agar: Good growth, restricted, rather flat, edges 

 lobate, surface warty, glistening, first pale orange, later ocher-yellow; con- 

 sistency crumbly. After 5 to 6 weeks, the growth is paler with many small, 

 round, raised, yellow secondary colonies. 



Paraffin: Readily utilized as a source of carbon. 



Phenol: Not utilized. 



Source: Probably soil. 



Remarks: Closely related to Nocardia corallina. 



