36 



THE ACTINOMYCETES, Vol. II 



so. Aerial hyphae produced; they vary from 

 rudimentary to long branching. Some may 

 produce chains of spores (Fig. 11). 



Sucrose nitrate agar: Growth thin, spread- 

 ing, orange. No aerial mycelium. No soluble 

 pigment. 



Peptone-beef extract agar: Growth much 

 folded, light yellow, becoming deep yellow 

 to yellowish-red. No soluble pigment. 



Yeast -glucose agar: Growth flat to 

 wrinkled, beige to dark pink. Some produce 

 white aerial hyphae. 



Potato: Growth much wrinkled, whitish, 

 becoming yellow to almost brick-red. 



Gelatin: Growth yellowish on surface. No 

 liquefaction. 



Milk: Orange-colored ring. No coagula- 

 tion; no peptonization. 



Starch agar: Growth restricted, scant, 

 orange. No diastatic action. 



Blood serum: No liquefaction. 



Carbohydrate utilization: See Table 2. 



Nitrate reduction: Positive. 



Oxygen demand: Aerobic. According to 

 Chalmers and Christopherson (1916), it may 

 also grow anaerobically. 



Temperature: Optimum 37°C. Some 

 strains grow readily at 28°C. 



Pathogenicity: Transmissible to rabbits 

 and guinea pigs, but not to mice. 



Source: Human infections and soil. 



Remarks: A number of strains of acid-fast 

 actinomycetes isolated from human lesions 

 have deviated in certain particulars from 

 the description of N. asteroides, but not 

 sufficiently to warrant separation as different 

 species. According to Gordon and Mihm, all 

 strains of N. asteroides form whitish aerial 

 hyphae, these varying from rudimentary to 

 much branching. The following characteris- 

 tics were considered the most valuable in the 

 identification of the species: development of 

 filamentous colonies with aerial hyphae; fail- 

 ure to hydrolyze casein and to dissolve the 

 crystals of tyrosine and xanthine; acid pro- 

 duction from glucose and glycerol; failure to 



form acid from arabinose, lactose, mannitol, 

 inositol, and xylose; utilization of acetate, 

 malate, propionate, pyruvate, and succinate, 

 but not benzoate. 



Numerous varieties of this species have 

 been described. It is sufficient to mention 

 N. crateriformis, N. gypsoides, and N. pseudo- 

 carneus (Gordon and Alihm, 1957). 



Type culture: IMRU* 3308; also 504. 



7. Nocardia atlantica (Humm and Shep- 

 ard, 1946) Waksman (Humm, H. J. and 

 Shepard, K. S. Duke Univ. Marine Sta. Bull. 

 3: 78, 1946). 



Synonym: Proactinomyces atlanticus. 



Morphology: Hyphae long, branching, 

 breaking up into rods and cocci, 0.5 to 0.7 m- 

 Involution forms in old cultures. Nonacid- 

 fast. Aerial mycelium not produced. 



Synthetic and organic media: Growth 

 bright yellow or yellow-orange, smooth, com- 

 pact, of a doughy consistency. Colonies flat 

 with slightly raised center. Soluble pigments 

 none. Mineral sources of nitrogen utilized. 



Gelatin liquefaction: Positive. 



Agar: Liquefied. 



Milk: Coagulation rapid, acidified; pep- 

 tonization slow. 



Nitrate reduction: Positive. 



Starch: Hydrolyzed. 



Cellulose: Decomposed. 



Chitin: Decomposed. 



Agar: Slowly digested. 



Alginic acid: Decomposed. 



Carbon sources: Acid produced from arab- 

 inose, xylose, rhamnose, raftinose, fructose, 

 galactose, sucrose, gum arabic. No acid 

 from lactose, dulcitol, mannitol, or sorbitol. 

 Organic acids utilized: gluconic, lactic, malo- 

 nic. Organic acids not utilized: acetic, 

 butyric, citric, etc. 



Optimum temperature: 28-oO°C. 



Habitat: Marine algae and marine sedi- 

 ments. 



* These designations represent the various cul- 

 ture collections where the type cultures are de- 

 posited. 



