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THE ACTINOAIYCETES, Vol. I 



tures were characterized by paper chroma- 

 tography using agar blocks, by behavior on 

 agar plates incorporating ion-exchange res- 

 ins, and by ultraviolet absorption spectrum 

 (to detect polyene substances). About half, 

 or 195 cultures, produced a mixture of anti- 

 biotics of both polyene and nonpolyene type. 

 A detailed treatment of these and various 

 other antibiotics produced by actinomycetes 

 will be presented in Volume III. 



Antitumor Agents 



Various actinomycetes are able to exert a 

 repressive effect against certain forms of 

 cancer and to produce cytologically active 

 substances. Attention has already been di- 

 rected to the effect of the actinomycins, a 

 group of antibiotics with marked cytologic 

 properties. Azaserine is another group of 

 compounds that are highly active against 

 various sarcomas. A similarity in this activ- 

 ity and that against the yeast Klockera brevis 

 was found; this made it possible to use ac- 

 tivity against the latter in studying the puri- 

 fication of the antibiotic. Sarkomycin, iso- 

 lated by Umezawa et al. in 1953, has since 

 been studied extensively by Hooper and 

 others. It was found to be active against ex- 

 perimental tumors, but did not have a great 



effect in human tumors. The same may be 

 said of another antitumor agent designated 

 as carzinophilin. A number of other sub- 

 stances (DON, mitomycin, sulfocidin) were 

 found to exei't marked antitumor activity, 

 but none of these has as yet found any prac- 

 tical application in the control of tumors in 

 man (Osato et at.). 



Cavalli-Sforza et al. found a high fre- 

 quency of antimitotic activity in the meta- 

 bolic products of soil microorganisms. With 

 the use of Allium cepa root tips, they ob- 

 served active antimitotic strains among 

 fungi and actinomycetes. There was no defi- 

 nite correlation, however, between antil)iotic 

 and antimitotic activity in the prepara- 

 tions thus obtained. 



Antiprotozoan, Antiviral, and Anti- 

 phage Agents 



Various actinomycetes are able to form 

 substances that exert antiprotozoan effects. 

 This is true particularly of such antibiotics 

 as streptocin, trichomycin, and other sub- 

 stances active upon trichomonads; of puro- 

 mycin and other agents active upon trypan- 

 osomes; and of anisomycin active upon 

 Endamoeba. This field has not yet been suffi 

 ciently explored, but it has marked poten 



Figure 92. The use of bacterial strains sensitive and resistant to a given antil)i()tic lor the identifi- 

 cation of the particular antibiotic. E. coli strains (from right to left): streptomycin-resistant, strejito- 

 mycin-dependent, and streptomycin-sensitive. The plates were streaked from top to bottom: original 

 streptomycin-producing iS. c/riseiis; culture producing an unknown antibiotic not of the streptomycin 

 type; an unknown streijtoinycin-])roducing culture. 



