32 



NATURE, FORMATION, AND ACTIVITIES 



Production of the Same Antibiotic by 

 Different Species 



111 \'iew of the fact that antibiotic-produc- 

 ing organisms are biological systems, one 

 may expect considerable variation, not only 

 of a (luantitative but also of a qualitative 

 nature, among the species and strains pro- 

 ducing the same type of antibiotic. Once a 

 given antibiotic has been recognized, it is a 

 common practice to try to increase the yield 

 by strain selection, impro\'ement in composi- 

 tion of media, and changes in environmental 

 conditions such as aeration and temperature. 



The production of the same antibiotic or 

 closely related forms by difTerent organisms 

 is recognized for such therapeutically im- 

 portant compounds as streptomycin, tetra- 

 cycline, neomycin, actinomycin, and various 

 others, notably the polyenes. 



The ability of species other than S. griseus 

 to produce streptomycin was first demon- 

 strated by Johnstone and Waksman (1948). 

 It has since been established that strepto- 

 mycin and the streptomycin group of anti- 

 liiotics are produced by a ^-ariety of organ- 

 isms found among the different series of the 

 genus Streptomyces (Volume II, Chapter ()). 

 These include (Okami ct al., 1959): (1) tuft- 

 pi'oducing organisms with .straight aerial 

 mycelium: ^>. griseus, S. bikiniensis, S. 

 rameus; (2) spiral-producing organisms: S. 

 humidus; (3) verticil-producing organisms: 

 S. reticuli, S. griseocorneus, S. mashuensis. 

 S. griseus produces streptomycin and man- 



Table 10 



Classijicdlio'ii of acliii(niiycin-pr<i(hui>uj organ isms 

 (Corbaz et al., 1957) 



* Brockmann system of nomenclature used. 



nosidostrcptomycin; S. hunii<lus forms dihy- 

 drostreptomycin (Kavanagh et al., 1960); 

 and S. griseocarneus forms hydroxystrepto- 

 myciii. 



Neomycin and the neomycin group of 

 antibiotics are produced by numerous strains 

 of »S'. fradiae, S. roseojiavus, S. albogriseolus, 

 S. kanamyeeticus, and by a variety of other 

 organisms (Waksman et at., 1958). This 

 group comprises neomycins B and C, 

 neamine, catenulin, kanamycin, paromo- 

 mycin, and a number of other compounds, 

 the exact chemical nature of which is still 

 undetermined. 



The tetracyclines comprise a variety of 

 compounds, including chlortetracycline, oxy- 

 tetracycline, tetracycline, demethylchlorte- 

 tracycline, and others. These are produced by 

 different organisms, including S. aureo- 

 faciens, S. rimosus, certain members of the 

 »S. fiavus group, and others. 



A number of organisms are now known to 

 1)6 capable of producing actinomycins; they 

 include S. antihioticus, S. flavus, S. flaveolus, 

 S. parvus, S. chrysomaUus, S. parvuUus, and 

 S. ceUulosae. Some of the polyenes are pro- 

 duced by a large num})er of species and 

 varieties (Vajima, 1955). Blinov (1958) 

 demonstrated that the candicidin-type poly- 

 ene is produced l)y at least 11 different 

 organisms. 



Further information on the chemical rela- 

 tionships of the various groups of antibiotics 

 is given in Chapter 6. 



A very interesting relationship between 

 micr()l)ial specificity and chemical nature of 

 antibiotics produced is found among the 

 actinomycins (Waksman, Geiger, and Rey- 

 nolds, 194()). Corbaz et al. (1957) demon- 

 strated (Table 10) that although different 

 species of Streptomyccs are capable of produc- 

 ing actinomycin, the chemical composition 

 of the antibiotic differs. In addition to these 

 organisms, other actinomycetes as well are 

 capable of producing actinomycin, as shown 

 for Micromonospora sp. (Fisher et al., 1951). 



