6 ACTINOMYCETES 



be recognized, as will be shown later. Thus, one could recognize such well- 

 established types as S. albus, S. griseus, S. lavendulae, S. flavus, S. coelicolor, 

 and certain others. The various species within a group could be considered 

 as related to a given type. This is possible where a large number of isolates 

 are available. 



Numerous systems for the classification of the various groups of actino- 

 mycetes have been proposed. Two of these are most comprehensive and 

 are, therefore, presented here. One is that of Krassilnikov, and the other, 

 that of Waksman and Henrici, as included in Bergey's Manual. 



Classification System of Krassilnikov 



A. Sporophores branching monopodially. 



I. Spiral -shaped sporophores, produced on hyphae of aerial mycelium. 

 1. Spores spherical or oval. 



a. Cultures colorless, not producing any pigmentation. 

 a 1 . Aerial mycelium white. 



a 2 . Saprophytes, living on dead material. 



Streptomyces albus 

 b 2 . Parasites. 



a 3 . Living in bodies of men and animals. 



Streptomyces bovis 

 b 3 . Living on plants. 



Streptomyces totschidlowskii 

 b 1 . Aerial mycelium dark gray. 



Streptomyces griseus 

 c 1 . Aerial mycelium green. 



Streptomyces glaucus 



b. Cultures pigmented blue. 



a 1 . Pigment of the anthocyanin type, similar to litmus. 



Streptomyces coelicolor 

 b 1 . Blue pigment not changing with acidity of medium. 



Streptomyces cyaneus 



c. Cultures violet, forming two basic pigments (red and blue), 

 both dissolved into the substrate. 



a 1 . Cultures not forming any fluorescent substance in liquid 

 media .... Streptomyces violaceus 



b 1 . Cultures producing in synthetic media a fluorescent sub- 

 stance of blue-green color similar to pyocyanin. 

 Streptomyces pluricolor 



d. Cultures black-violet, forming red and blue pigments, as well 



