FAMILY ACTINOMYCETACEAE 



903 



Gelatin stab: Nailhead; line of stab 

 arborescent. No liquefaction. 



Agar colonies : Round, convex, or um- 

 bonate, smooth, pink, shining or matte; 

 border lighter, edge filamentous or with 

 arborescent projections. Deep colonies: 

 Burrs, or lens-shaped, with arborescent 

 projections. In their verj'' early stages 

 colonies consist of branching filamentous 

 rods. As the colony grows, the cells in 

 the interior break up into short rods and 

 cocci which eventually form the mass of 

 the colony. Cells on the outside remain 

 filamentous, giving the colony a burr- 

 like appearance, and often forming long 

 arborescent processes. 



Agar slant: Filiform, convex, smooth, 

 pink, shining or matte; arborescent or 

 with projections from undulate border. 



Litmus milk: Alkaline. Reddish pel- 

 licle. 



Glycerol potato: Filiform, raised, dry, 

 wrinkled, yellomsh-brown to coral red. 



Broth: Usuallj^ turbid. Pink scum. 



Dorset's egg medium: Filiform, raised, 

 dry, wrinkled, orange. 



Loeffler's medium: Similar to growth 

 on Dorset's egg medium, but pink. 



Nitrites produced from nitrates. 



Acid from glycerol and glucose with 

 some strains. Xo acid or gas from su- 

 crose, maltose or lactose. 



Phenol and m-cresol are utilized. 

 Some strains utilize naphthalene. (Gray 

 and Thornton.) Some strains utilize 

 phenol or m-cresol (Jensen). 



Optimum pH 6.8 to 8.0. 



Optimum temperature 22" to 25°C. 



Distinctive characters : Soil organism 

 forming M ycobacterium-like colonies after 

 2 to 4 days on simple media. Pale pink 

 chromogenesis . Xailhead growth in gela- 

 tin stab. Branching rods and short 

 filaments. 



Source : Seventy-four strains isolated 

 from soils in Great Britain and Australia. 



Habitat: Soil. 



13. Nocardia globerula (Gray) co^nb. 

 nov. (Mycobacterium globerulum Gray, 



Proc. Roy. Soc. London, B, lOS, 1928, 

 265; Proaciinomyces globerulus Reed, in 

 Manual, 5th ed., 1939, 838.) From Latin 

 globus, a sphere. 



Description from Gray (loc. cit.) and 

 from Bynoe (Thesis, McGill University, 

 Montreal, 1931). 



Curved rods and fUaments : 1 by 2 to 9 

 microns, with many coccoid cells, es- 

 pecially in old cultures. Rods and fila- 

 ments are frequently irregularly swollen. 

 Xot acid-fast. Capsules may be present. 

 Gram-positive. 



Gelatin : After 19 days surface colonies 

 irregularly round, 1 to 2 nma in diameter, 

 convex, light buff, smooth, shining; edge 

 entire. Deep colonies : Round, with en- 

 tire edge. 



Gelatin stab : After 8 days nailhead, 

 irregularly round, convex, pinkish-white, 

 smooth, shining; line of stab erose. 



Agar : After 4 days surface colonies ir- 

 regularly round, 3 to 5 mm in diameter, 

 convex, white, smooth, shining; edge un- 

 dulate, erose. After 7 days, more con- 

 vex and of a watery appearance. Deep 

 colonies : After 4 days, lens-shaped. 



Agar slant : After 3 days, filiform, fiat, 

 watery; edge irregular. 



Nutrient and peptone broth : Turbid 

 with \'iscous suspension. 



Indole not formed. 



Litmus milk: Alkaline. 



Glycerol potato: After 24 hours, fili- 

 form, moist, smooth, pale pink. 



Dorset's egg medium: After 2 weeks, 

 spreading, raised, moist, orange -colored. 



Loeffler's medium: Growth jas on 

 Dorset's egg medium, but salmon-colored. 



Xitrites not produced from nitrates. 



Xo acid from glucose, lactose, maltose, 

 sucrose or glycerol. 



Phenol is utilized. 



Indole agar : Blue crystals of indigotin 

 formed. 



Optimum temperature 25° to 28°C. 



Optimum pH 6.8 to 7.6. 



Distinctive characters : This organism 

 resembles most closely Nocardia 

 corallina. It is distinguished by pro- 



