230 



THE ACTINOMYCETES, Vol. I 



Table 63 



Antibacterial activities of the various 

 streptomycins (Rake et al.) 



* All figures are given in terms of weight of the 

 trihydrochlorides. On the basis of assays with A'. 

 pneumoniae, the streptomycin and dihydrostrep- 

 tomycin would have an activity of 820 units per 

 mg, the mannosidostreptomycin an activity of 236 

 units per mg, and the dihydromannosidostrepto- 

 mycin 228 units per mg. 



t Strains of M . tubcrrulosi.'i freshly isolated 

 from human cases. 



raffinose-negative, but are xjdose-, manni- 

 tol-, and lactose-positive. The various strep- 

 tomycin- and streptothricin - producing 

 strains belong to this group. 



II. Those organisms that show the same 

 type of carbon utilization. These include 

 strains of S. griseus, S. olivaceus, and S. 

 poolensis. 



Groups III-VI comprised mostly strep- 

 tothricin-, chloramphenicol-, and tetra-cy- 

 cline-forming groups. 



A combination of chemical, physical, and 

 biological properties of the antibiotics pro- 

 duced by actinomycetes can be utilized in 

 developing a proper system of classification, 

 as will be shown in Chapter 32 (Volume III). 

 At present, some 20 different categories of 

 antibiotics may be recognized. Some of these 

 are the following: 



1. The actinomycins and other polypep- 

 tides. 



2. The glucosidic antibiotics. 



3. The macrolides. 



4. The pigmented antibiotics. 



5. Chloramphenicol. 



6. The tetracyclines. 



P'iGURE 87. Antibiotic spectrum of S. fradiae 

 (top \oho\iom: Saccharomyces ccrevisiae, Aspergil- 

 lus nigcr, Scrr. marcescens, Micrococcus iysodeikti- 

 cus). 



