146 ACTINOMYCETES 



20. Nocardia mesenterica (Orla-Jensen) Waksman and Henrici. (Orla- 

 Jensen, S., The lactic acid bacteria, 1919, 181; Jensen, H. L., Proc. Lin- 

 nean Soc. N. S. Wales, 57, 1932, 373.) 



Mycelium: Extensive, composed of richly branching hyphae of a some- 

 what variable thickness, 0.4-0.8 n; no aerial hyphae are seen. With increas- 

 ing age the hyphae divide into fragments of varying sizes and shapes, 

 partly diphtheroid rods, but no real cocci. There is, particularly in richer 

 media, a tendency to form large, swollen, fusiform to almost spherical 

 cells, up to 3.5 n in diameter. These may stain intensely with carbol 

 fuchsin; when transferred to fresh media, they germinate and produce a 

 new mycelium. 



Glucose-nutrient agar: Good growth, restricted, with undulate edges, 

 surface with high transverse folds, cream-colored; the consistency is firm 

 and cartilaginous after 2 days, later looser and more brittle. Growth at 28° 

 to 30° rather scant; smooth, soft, glistening, cream-colored smear. 



Potato: Scant growth; restricted, soft, cream-colored smear. 



Gelatin: Good growth; finely arborescent, cream-colored growth in the 

 stab; raised, folded, pale yellow, surface colony. No liquefaction. 



Milk: At 28° to 30°C, small cream-colored granules along the tube; the 

 milk undergoes no visible changes within 4 weeks. No proteolytic action. 



Starch: Hydrolysis. 



Cellulose: No decomposition. 



Nutrient broth: Good growth; voluminous, flaky, whitish sediment; 

 broth clear. 



Nitrate: No reduction. 



Sucrose: Inversion. 



Glucose-asparagine agar: Fair growth, narrow, raised, granular, very 

 pale yellow, glistening; condensation water-clear, with small granules. 

 At 30°C only scant growth consisting of small irregular white granules, 

 growing deeply into the agar. 



Sabouraud's agar: Excellent growth, spreading, at first flat and smooth, 

 pale straw-yellow, perfectly hard and cartilaginous, later raised and strongly 

 folded, of a loose, curd-like consistency, bright lemon-yellow. Growth at 

 28° to 30°C only fair, restricted, folded, cream-colored, soon becoming soft 

 and smeary. 



Source: Fermented beets. 



Remarks: Sodium nitrate, ammonium phosphate, and asparagine uti- 

 lized, although these are inferior to peptone as sources of nitrogen. 



21. Nocardia albicans (Krassilnikov) comb. nov. (Krassilnikov, N. A., 

 Actinomycetales, Akad. Nauk. USSR, Moskau, 1941, 71.) 



