188 



THE ACTINOMYCOTIC, Vol. II 





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Figure 34. Sporophores of S. ralvus (Reproduced from: Backus, E. J. et al. Antibiotics & Chemo- 

 therapy 7: 530, 1957). 



Antagonistic properties: Weak. 



Habitat : Soil. 



Remarks: Certain varieties of this species 

 have also been described. This is true, for 

 example, of A. fasciculus, which Krassilni- 

 kov himself considered as a variety of S. 

 candid 'us; it is also true of .4. farinosus 

 Krassilnikov and of .4. candidus var. albo- 

 roseus described by Gause et al. (1957). 

 S. nitrosporeus Okami (1952) appears to be 

 closely related, if not identical to it. Ett- 

 lrnger et al. (1958) consider this organism 

 as related to S. griseus. 



Type culture: [MRU 3416. 



42. Streptomyces rum sens Hickey et al., 

 L952 (Hickey, U. J., Coram, C. J., Hidy, 



P. H., Cohen, I. R., Nager, U. F. B., and 

 Kropp, E. Antibiotics & Chemotherapy 

 2:472-483, 1952). 



Morphology: Sporophores straight or 

 curved, not forming any spirals. Spores 

 globose, 1.0 to 1.3 by 1.3 to 2.6 n (Fig. 35). 



Calcium malate agar: Growth gray to 

 rose-gray; reverse yellow to tan. No soluble 

 pigment. 



Yeast extract-casein digest agar: Growth 

 effuse to convex, edge filamentous; reverse 

 brown. Aerial mycelium powdery, varying 

 from gray-white to gray. No soluble pig- 

 ment. 



Acid-glucose-peptone agar: Growth at 

 first white, then tan. Aerial mycelium faintly 



