SERIES AM) SPECIES OF GENUS STREPTOMYCES 



12!) 



following species: S. Jliirus, S. Jhirorin US, S. 



flavogriseus, S. chrysomallus, S. celluloflavus, 

 and S. viridans. 



IV. Series Ruber 



( 'haracU ristic Propertu s 



a. Sporophores straight or spiral- 

 shaped. 



h. Substrate growth pink, red to red- 

 orange t<» purple-red; pigment insoluble. 

 Aerial mycelium thin, rose-white. 



c. Melanin-negative. 



The Ruber series comprises a large, highly 

 heterogeneous group of organisms. Members 

 of this series have been known since 1888, 

 when Mace described an organism under 

 the name of Cladothrix rubra. Numerous 

 other cultures under different names were 

 later placed in this group. 



The Ruber series is characterized by a 

 bright red, red-orange, or rose-red substrate 

 growth, the color depending on the composi- 

 tion of the medium and on conditions of 

 cultivation. The cultures may show con- 

 siderable variation in color of the substrate 

 mycelium, from purple-red to light rose. The 

 pigment is usually not excreted into the 

 medium, unless the latter contains fatty sub- 

 stances in which the pigment is soluble. The 

 aerial mycelium is not well developed; it is 

 usually produced on synthetic media as a 

 thin, rose-white cover, or it is formed only 

 in isolated sectors or spots. Tin 1 sporophores 

 are straighl or spiral-shaped; the spores are 

 spherical to oval, 0.7 to 0.8 by 0.8 to 1.0 M . 



The members of the Ruber series are not 

 very strongly proteolytic or diastatic. Su- 

 crose is readily inverted. Some of the species 

 belonging to this series are active producers 

 of anl ibiotics. 



Baldacci did nol list a Ruber series, but 

 one designated as "roseus," which is close 

 enough to be considered similar to it. An- 

 other was designated as " m< ianospOTi US," 



which is also close to the u ruber" series. 

 Gause et al. (1957) divided the series into 



three subgroups on the basis of structure of 

 the sporophores, namely, spiral-shaped, 

 straight, and tuft-forming; the lasl appar- 

 ently includes verticil-forming types. 



Some of these organism- may be con- 

 sidered as forms intermediate in transition 

 to the true chromogenic type-. Among the 

 forms closely related to this series, one may 

 include, for example, S. melanocyclus, S. 

 melanosporeus, S. melanogenes, and possibly 

 also S. erythrochromogenes, S. roseochromo- 

 genes, and S. purpureochromogenes. The 

 Ruber series is also related to the Fradiae 

 and Flavus series, notably through such spe- 

 cies as S. roseoflavus and possibly S. micro- 

 flavus. 



Certain forms that may be considered as 

 species of Nocardia are frequently included 

 in this and in the next series. Somet imes even 

 a new series is created for them, as was done 

 by Baldacci (1942) for "madurae." 



S. albosporeus may be considered as a 

 subgroup of the Ruber series. It is charac- 

 terized by the formation of a rose-colored or 

 red to brown substrate growth and a white 

 aerial mycelium. Cultures belonging to this 

 subgroup are characterized by strong pro- 

 teolytic activity and by weak diastatic ac- 

 tion. The sporophores are straight, with 

 some close spirals. The first representatives 

 of this subgroup were isolated by Krain.-kv 

 in I'M 1 and by Waksman and ( 'urtis in L916. 



The separation of members of this series 

 on the basis of carbon utilization has been 

 suggested by Zahner and Kt t linger I 1957 1, as 

 shown in Table 15. 



Although a large number of species found 

 in the literature may be included in the 

 Ruber series, only a few have been suffi- 

 ciently described. It is sufficient to mention 

 S. ruber, S. niveoruber, S. albospon us, and S. 



i r yi h nil US. 



