FAMILY II. ACTINOMYCETACEAE 



741 



Good growth in media prepared with dis- 

 tilled water and in all salinities through 6 

 per cent (sea salt), but slightly less vigorous 

 in concentrations above 5 per cent. Pigmen- 

 tation and morphological characteristics ap- 

 parently the same at all salinities. 



Source: Isolated frequently from inter- 

 tidal marine sediments and beach sand in 

 North Carolina and Florida. 



Habitat: Found in marine sediments of 

 the South Atlantic coast of the United 

 States. 



45. Nocardia atlantica (Humm and 

 Shepard, 1946) Waksman, comb. nov. (Pro- 

 actinomyces atlanticus Humm and Shepard, 

 Duke Univ. Marine Sta. Bull., 3, 1946, 78.) 



at.lan'ti.ca. M.L. adj. atlanticus pertain- 

 ing to the Atlantic Ocean. 



Vegetative growth: Young colonies com- 

 posed of slender filaments of various 

 lengths, occasionally branched. Diameter of 

 filaments 0.4 to 0.6 micron. Older colonies 

 composed entirely of coccoid cells 0.5 to 0.7 

 micron in diameter, occurring singly or 

 variously grouped. Non-motile. Not acid- 

 fast. Gram-positive. 



Gelatin: Liquefaction crateriform at first, 

 becoming stratiform after about one week at 

 20° to 23° C. 



Agar colonies: Orange-yellow on all 

 media. No variant colonies observed on 

 poured or streaked plates. Colonies flat 

 with slightly raised center, the margin un- 

 dulate or crenate and growing slowly out- 

 ward just beneath the surface of the agar. 

 Older colonies become characteristically 

 divided into sectors. Thickly seeded colonies 

 exhibit a mutual antagonism so that their 

 margins do not grow together. No soluble 

 pigments. 



Agar slant: Orange-yellow, filiform 

 streak, margin slowly spreading just be- 

 neath surface of agar. Surface of growth 

 rather dull, consistency butyrous. Old 

 slants may develop sectored appearance. 



Broth: Usually clear with yellow, granu- 

 lar growth adherent to sides of tube. Heavy 

 growth ring may develop at surface, floccu- 

 lent sediment. Pellicle usually lacking, 

 though thin, fragile, surface film may de- 

 velop. 



Milk: Rapid coagulation, acid; slow pep- 

 tonization. 



Indole not produced. Indigotin not pro- 

 duced from indole. 



Hydrogen sulfide not produced. 



Acid from arabinose, xylose, rhamnose, 

 raffinose, fructose, galactose, glucose, man- 

 nose, cellobiose, maltose, sucrose, salicin, 

 gum arable and Karaya gum. No acid from 

 lactose, dulcitol, mannitol or sorbitol. 

 Sorbitol slowly utilized without acid pro- 

 duction. 



Gluconic, lactic and malonic acids uti- 

 lized. Acetic, butyric, citric, malic, maleic, 

 oxalic, propionic and iso-valeric acids not 

 utilized. 



d-Arginine and glutamic acid utilized as 

 sources of both nitrogen and carbon, dl- 

 Alanine, aspartic acid, cystine, glycine, 

 1-leucine, dl-|8-phenylalanine (slowly), 

 1-proline and tyrosine utilized only as 

 nitrogen source. Creatine not utilized. 

 Glucosamine-HCl utilized with acid produc- 

 tion. 



Acetjdmethylcarbinol not produced. 



Starch is hydrolyzed. 



Cellulose, chitin and alginic acid are 

 attacked. 



Seaweed gels: Agar slowly digested; 

 softened, not liquefied, evident only by 

 means of the iodine test. Gelase field narrow, 

 margin fading. Irish moss gel also slowly 

 attacked. 



Nitrites vigorously produced from ni- 

 trates. 



Ammonia, nitrite or nitrate slowly uti- 

 lized as nitrogen sources. Ammonia pro- 

 duced slowly from nitrite, nitrate, aspara- 

 gine and peptone. Urea utilized as a nitrogen 

 source, but ammonia does not accumulate. 



Catalase-positive. 



Aerobic. 



Optimum temperature, between 28° and 

 30° C. 



Good growth in media prepared with dis- 

 tilled water and in all salinities through 6 

 per cent (sea salt). Pigmentation and mor- 

 phological characteristics apparently the 

 same at all salinities. 



Source: Isolated from seaweed. 



Habitat: Probably marine algae and ma- 

 rine sediments of the South Atlantic coast of 

 the United States. 



