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.
