Chapter VIII _147— Distribution 



waters as well as in marine bottom deposits bas also been reported (522). 

 RuBENTSCHiK (371) isolated from the salt liman of the Black sea an 

 organism, A. vielano genes, wbicb decomposed cellulose. ZoBell, 

 Grant, and Haas (521) included species of Strc'ptoviyces and Micro- 

 inonospora among the organisms which attack aliphatic, aromatic, naph- 

 thenic, and olefinic hydrocarbons under aerobic conditions. These 

 organisms were said to be widely distributed in sea water and in marine 

 mud. 



Occurrence of Actinomycetes in Dust and on Exposed Surfaces 



of Plants:— Actinomycetes, especially forms producing aerial mycelium, 

 are abundant in the dust of the atmosphere and are found on all ex- 

 posed surfaces. They are largely derived from the soil, as is indicated 

 by their similarity to the soil-inhabiting forms. As has been pointed out, 



Table 37: Numbers of microorganisms in an undrained feat bog in Florida (473): — 

 Numbers in 1 gm of moist peat 



the first observations on the occurrence of actinomycetes in the dust were 

 made by Miquel, in 1883, in his studies on the microorganisms of the 

 atmosphere. Since then, many similar reports have been made. The 

 universal presence of these organisms and their ability to thrive on traces 

 of organic materials often led to generalizations that seemed hardly 

 justified. It is sufficient to mention, for example, the organism desig- 

 nated by Beijerinck as B. oligocarhophilus, a form later (251) shown 

 to be an actinomyces. As the name indicates, it was believed capable 

 of obtaining its carbon and energy from ever)'where, including the dust 

 of the atmosphere. Even less justified is the assertion of Emerson 

 (104) that actinomycetes may be looked upon as organisms capable of 

 fixing atmospheric nitrogen. This assertion was based upon the devel- 

 opment of actinomyces colonies when soil was plated out on nitrogen- 

 free agar media. 



The assertion (262fl) that living organisms resembling actinomy- 

 cetes were discovered in Pre-Cambrian rock and in Pliocene rock has 

 never been confirmed. The chances are that thev were derived from the 



