738 



ORDER V. ACTINOMYCETALES 



rarely producing an aerial mycelium, though 

 in certain strains it may occur frequently. 

 Retains the mycelium form for long periods. 

 Not acid-fast. 



Gelatin: Liquefaction. 



In the young colony an orange-yellow to 

 orange-red, intercellular pigment is pro- 

 duced on all media, which may or may not 

 change to black as the culture ages. 



Milk: No digestion. 



Starch is hydrolyzed. 



Paraffin not utilized. 



Source: Isolated from soil. 



Habitat: Soil. 



40. Nocardia rhodnii (Erikson, 1935) 

 Waksman and Henrici, 1948. (Actinomyces 

 rhodnii Erikson, Med. Res. Council Spec. 

 Rept. Ser. 203, 1935, 37; Waksman and Hen- 

 rici, in Manual, 6th ed., 1948, 914.) 



rhod'ni.i. M.L. mas.n. Rhodnius generic 

 name of an insect; M.L. gen.noun rhodnii of 

 Rhodnius. 



In early stages, the minute colonies are 

 composed of hyphal segments arranged in 

 angular apposition, the aerial mycelium 

 being short and straight. Later the growth 

 becomes extensive and spreading, made up 

 partly of long, genuinely branching fila- 

 ments and partly of short segments exhibit- 

 ing slipping branching, each giving rise to 

 aerial hyphae. After 2 weeks the angular 

 branching is very marked, delicate spread- 

 ing herring-bone patterns being formed. 



Gelatin: Rapid liquefaction; pale pink 

 colonies in superficial pellicle and sediment. 



Coon's agar: Colorless, pinpoint colonies. 



Czapek's agar: Minute, colorless, round 

 colonies. 



Glucose agar: Abundant, coral -pink, con- 

 voluted, piled-up growth. 



Glycerol agar: Extensive growth, dull 

 pink colonies round and umbilicated, be- 

 coming piled-up and deeper coral; later 

 partly submerged. 



Dorset's egg medium: Salmon-pink, 

 granular membrane; later piled up. 



Serum agar: Extensive, reddish, confluent 

 mass, granular, tending to be piled up; the 

 medium around the growth shows reddish 

 coloration in 2 weeks. 



Inspissated serum: Smooth, round, pale 

 pink colonies, centrally depressed and ir- 



regularly coiled larger mass; no liquefac- 

 tion. 



Broth: Salmon-pink flakes in sediment 

 and colonies on surface; after 2 weeks, 

 abundant growth and discoloration of 

 medium. 



Glucose broth: Thin, pink, superflcial 

 pellicle, easily breaking up, and small flakes 

 in sediment; after 2 weeks abundant growth 

 extending up tube. 



Synthetic sucrose solution: Colorless to 

 pink colonies in superficial pellicle and 

 minute, round, white colonies coherent in 

 loosely branching mass in sediment. 



Milk: Bright orange growth; medium un- 

 changed. 



Potato agar: Abundant, pink growth, 

 piled up; scant stiff white aerial mycelium 

 at top of slant. 



Source: Isolated from the reduvid bug, 

 Rhodnius prolixus. 



Habitat: Presumably insects. 



41. Nocardia gardneri (Waksman, 1942) 

 Waksman and Henrici, 1948. (Actinomycete, 

 Gardner and Chain, Brit. Jour. Exp. Path., 

 £3, 1942, 123; Proactinomyces gardneri Waks- 

 man, in Waksman, Horning, Welsch and 

 Woodruff, Soil Sci., 54, 1942, 289; Waksman 

 and Henrici, in Manual, 6th ed., 1948, 914.) 



gard'ne.ri. M.L. gen.noun gardneri of 

 Gardner; named for Prof. A. D. Gardner, 

 one of the two who first isolated this or- 

 ganism. 



Branching mycelium. Gram-positive. 



Gelatin: Cream-colored surface ring. 

 Rapid liquefaction. Green to greenish brown 

 soluble pigment gradually diffuses through 

 the liquefied portion. 



Nutrient agar: Cream-colored, elevated, 

 lichenoid growth, soft, not leathery; no 

 aerial mycelium; very faint brownish pig- 

 ment. 



Glucose agar: Brownish, lichenoid 

 growth, with wide, cream-colored edge; 

 white to grayish aerial mycelium gradually 

 covering surface. Reverse of growth yellow- 

 ish; no soluble pigment. 



Glucose-asparagine agar: Aerial mycelium 

 develops slowly. 



Tr3'ptone broth: Growth occurs as small 

 pellets at the base of the flask; later, a thin 

 surface pellicle appears which consists of a 



