( II V l» T K H ^ 



Distribiilioii in Nature 



Tlu' distribution in nature of any group 

 of livin<;- orfj;anisms, whether these are highei- 

 or lower forms of life, with or without th(^ 

 power of locomotion at least at one sta<i;e of 

 their development, depends on se\'(M"aI im- 

 portant factors: 



1. The nature of the substrate in or upon 

 which the particular organisms \Wv. 



2. The nature of the food supply available 

 to them as sources of energj' and for cell 

 synthesis. 



3. The nature of the environment, notabh^ 

 aeration, temperature, and rea(;tion. 



4. The biotic complex, or the specific na- 

 ture of other living systems with which the 

 particular organisms have to come in con- 

 tact, thereby possibly competing for space 

 and nutrients. 



The mode of nutrition of these organisms, 

 the synthesis of various chemical complexes, 

 the formation of waste products, and the 

 mechanisms (such as enzyme systems) 

 wherebj' these reactions are brought about, 

 — all depend, to a large extent, upon the 

 nature of the organisms, the available food 

 supply, and their ability to adapt themselves 

 to the particular environment. 



The wide occurrence of actinomycetes w'as 

 reported by many of the early investigators. 

 Those who did not recognize this fact fre- 

 quently reported, as the causative agents of 

 a particular infection, air contaminants 

 which they isolated. Others observed the 

 wide occurrence of the actinomycetes but 

 considered the organisms to be onlv differ- 



ent forms of the same general type. It is 

 sufficient to cite the following. 



Salei-azes, in 1895, spoke of different kinds 

 of "Streptothrix" capal^le of producing ac- 

 tinomycosis in man. He believed, however, 

 that actinomycosis could be caused by differ- 

 ent other forms, a situation he considered as 

 sufficient explanation for the variations fre- 

 Cjuently reported in the morphology and 

 biology of Actinomyces bovis. He also spoke 

 of the occurrence of ''Streptothrix" in air 

 and water. Although he considered them as 

 external saprophytes, li\'ing on vegetables 

 and cereals, he believed that they were ca- 

 pable of causing human and animal infec- 

 tions. The mouth was looked upon as the 

 portal of entry of the organisms. He believed 

 that they did not produce toxic secretion 

 products, but caused injury through their 

 actual vegetative development ("vegetabi- 

 lite") in the bod}-. 



Distribution of Actinomycetes 



Actinomycetes are widely distributed in 

 nature. They are found in virtually every 

 natural substrate; in the air we breathe, in 

 the water we drink, in the foodstuffs we 

 consume, and in the soil we walk on. Soils 

 and composts are particularly favorable for 

 their de\-elopment; they are found there in 

 great abimdance, both in numbers and in 

 kinds. The deep seas, however, do not offer 

 so fa\-orable a medium for their de\elop- 

 ment. Some substrates are ideal as perma- 

 nent habitats for the actinomycetes, where 



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