CHARACTERIZATION OF STREPTOMYCES SIM < II S 



77 



been suggested for species identification of 

 actinomycetes. Aoki (I'.)::.") L936) was thus 

 able to differentiate 1 km ween representatives 

 of three genera, Actinomyces, Nocardia, and 

 Streptomyces. By means of sonic vibrations, 

 Ludwigand Butchinson (1949) prepared an- 

 tigen suspensions satisfactory tor use in ag- 

 glutinin and precipitin reactions and for the 

 production of immune sera in rabbits. Use 

 of such suspensions in the identification of 

 actinomycetes was suggested by Yokoyama 

 and Ilata (1953) and Bata et al. (1953). A 

 purified antigen of a streptomycin-producing 

 strain was found active againsl immune sera 

 of the same strain, bu1 not against sera of 

 other antibiotic-producing organisms. These 

 investigators were thus able to establish the 

 close relationship of luteomycin- and chlor- 

 amphenicol-producing organisms. 



Ochoa and Boyos (1953) found a correla- 

 tion between microscopic morphology and 

 serological reactions which made it possible 

 to divide the actinomycetes into four 

 groups: Group 1, including species of Ac- 

 tinomyces and Nocardia; Group 2, made up 

 largely of Nocardia; Groups :> and 4, com- 

 prising species of Streptomyces. Slack it al. 

 (1051), however, found that antisera pre- 

 pared witli .1. bovis brought about low titer 

 agglutination of Nocardia and of two species 

 of Streptomyces. They concluded thai a close 

 antigenic relationship exists between mem- 

 bers of the genus Actinomyces and thai there 

 is a group relationship among Actinomyces, 

 Nocardia, and Streptomyces. Okami (1956) 

 found definite antigenic relationships be- 

 tween strains of closely related forms of ,S'. 

 lavendulae. See also Tanaka */ '//., 1 959. 



( 'In mical < 'omposition 



A detailed study of the chemical composi- 

 tion of cells of actinomycetes has been pre- 

 sented in Volume I (pp. L58 L63 1. 



The occurrence of specific chemical com- 

 pounds in the cells of the organisms suggests 

 possible differentiation between groups of 



actinomycetes. This is true, for example, of 

 the occurrence of diaminopimelic acid, a 

 constituent that may prove to be of generic 

 rather than specific significance. Romano 

 and Sohler (1956) and Sohler et al. (19581 

 have shown thai cell walls of streptomycetes 

 can be solubilized by lysozyme, suggesting 

 the presence of a mucopolysaccharide; on 

 the other hand, cell walls of nocardiae do 

 not possess this property. 



Ecology 



The natural substrate of an organism, es- 

 pecially diseased plants or animals, and com- 

 posts of stable manures and plant residues 

 at high temperatures, is of some systematic 

 significance. Various attempts have been 

 made to utilize the ecological characteristics 

 of the actinomycetes as a basis of classifica- 

 tion. Thus, the following rather broadly de- 

 fined ecological categories have been pro- 

 posed at various times to classify actino- 

 mycetes: 



a. Animal parasites. 



b. Plant parasites. 



c. Soil inhabitants. 



d. Water inhabitants. 



e. Mesophilic forms. 



f. Thermophilic forms. 



g. Inhabitants of acidic (pll .'! to 6.5) sub- 

 strates. 



h. Inhabitants of neutral to alkaline sub- 

 strates (pi 1 6.5 and above). 

 The temperature at which an organism is 

 grown greatly affects the nature and amount 

 of growth, the nature and extent of sporula- 

 tion, and the degree of formation of soluble 

 pigments. The optimum temperature for the 

 growth of most species of Streptomyces is be- 

 tween 25 and 30 C. Only a few of these or- 

 ganisms are thermophilic. Abilities to grow 

 under mesophilic and thermophilic condi- 

 tions have been recognized as import ant 

 criteria for establishing species and even 

 genera of actinomycetes and other microor- 

 ganisms. 



