Waksman — 28 — Actinomycetes 



ends; no spirals of fruiting branches. This group is the same as Group B of 

 Jensen. 



2. Typical forms— mycelium develops only at early stages of growth, then breaks 

 up into rod-shaped and coccoid bodies; smooth and rough colonies, dough-like con- 

 sistency; usually do not form aerial mycelium; similar to bacterial colonies; aerial 

 mycelium may form around colonies. 



The genus Nocardia can also be divided into two groups on the 

 basis of acid-fastness: 



1. Partly acid-fast organisms, which are nonproteolytic, nondiastatic, and utilize 

 paraffin; usually yellow, pink, or orange-red in color. 



2. Non-acid-fast organisms, which are diastatic, largely proteolytic, and do not 

 utilize paraffin; yellow, orange to black in color. 



Type Species: Nocardia farcinica Trevisan. QStreftothrix farcinica 

 Rossi-Doria; Oosfora farcinica Sauvageau and Radais; Actinomyces far- 

 cinicus Gasperini; Actinomyces hovis farcinicus Gasperini; Bacillus far- 

 cinicus Gasperini; Cladothrix farcinica Mace; Streptothrix farcini hovis 

 Kitt; Stre-ptothrix nocardii Foulerton; Discoviyces farcinicus Geodoelst; 

 Actinomyces nocardii Buchanan, and many others). 



Filaments 0.25/j. in thickness, branched. Markedly acid-fast. 



Gelatin colonies: Small, circular, transparent, glistening. 



Gelatin stab: No liquefaction. 



Agar colonies: Yellowish-white, irregular, refractive, filamentous. 



Agar slant: Grayish to yellowish-white, surface roughened. 



Broth: Clear, with granular sediment, often with gray pellicle. 



Litmus milk: Unchanged. 



Potato: Abundant, dull crumpled, whitish-yellow. 



Nitrites not produced from nitrates. 



No soluble pigment formed. 



Proteolytic action absent. 



Starch not hydrolyzed. 



Aerobic, facultative. 



Optimum temperature 37 °C. 



CoNANT and RosEBURY (75) recently presented (Table 2) a sum- 

 mary of some of the salient features of different species of Nocardia. 



Habitat: Associated with disease in cattle, resembling chronic tuberculosis. 

 Transmissible to guinea pigs, cattle, and sheep but not to rabbits, dogs, horses, or 

 monkeys. 



The last edition of Bergey's Manual contains descriptions of 33 species, 

 with a large nurhber of additional species only incompletely described. 



Genus III. Streptomyces Waksman and Henrici 



CStreptothrix Cohn; not Stre-ptothrix Corda; Actinomyces Harz; Discomyces 

 Rivolta; Actinocladothrix Afanassiev; Nocardia Trevisan; Micromyces Gruber; not 

 Micromyces Dangeard; Actinohacterium Haas; Carteria and Carterii Musgrave, 

 Clegg and Polk; Euactinomyces Langeron). 



