40 



THE ACTINOMYCETES, Vol. I 



Table 8 



Microbiological population of an undrained peat hog 



in Forida (Waksman and Purvis) 



Numbers in 1 gm of moist* peat, in thousands 



* Moisture content varied from 80.1 to 87.4 per 

 cent. 



(Silvey and Roach). They also occur in chlo- 

 rinated waters (Adams, 1929). 



Waksman and Purvis (1932) made a study 

 of the microbiological population of an un- 

 drained peat bog in Florida. The numbers 

 of actinomycetes were found (Table 8) to 

 decrease rapidly with depth. 



Hvid-Hansen (1951) reported the presence 

 of an anaerobic Actinomyces in ground water 

 containing hydrogen sulfide. This organism 

 produced in an organic medium formic acid, 

 propionic acid, and lactic acid. Since sulfate- 

 icducing bacteria are able to use these com- 

 pounds as hydrogen donors in an otherwise 

 autotrophic medium, a close symbiosis was 

 assumed to exist between the anaerobic ac- 

 tinomyces and the sulfate-reducing bacteria. 

 Six strains of the organism were isolated and 

 described. Further information on this or- 

 ganism, named A. hanseni, is given in Chap- 

 ter 24, Vol. II. 



The occurrence in fresh water of organisms 

 belonging to the genera Actinoplanes and 

 Strcjdo.sporangium has l)een reported by 

 Couch. 



Occurrence of Actinomycetes in Stable 

 Manures and Composts 



Just as the actinomycete population of the 

 soil is characterized chiefly by the geiuis 

 Strcptomyces, as lake waters and lake bot- 



toms are characterized by a population of 

 Micromonospora, and as the actinomycetes 

 causing human and animal diseases are lim- 

 ited primarily to the genera Actinomyces and 

 Nocardia, — so the actinomycetes living in 

 composts of stable manures and plant resi- 

 dues, especially high temperature composts, 

 are limited almost entirely to certain specific 

 genera related to Streptomyces and Micro- 

 ynonospora. Composts frecjuently attain tem- 

 peratures of 50 to 65°C and may even reach 

 80°C. This is due to the evolution of heat 

 resulting from the activities of the micro- 

 organisms bringing about the decomposition 

 of the plant and animal residues, especially 

 the carbohydrates and the proteins. The 

 compost must be thoroughly aerated to 

 bring this about, since an anaerobic environ- 

 ment does not favor rapid decomposition. 



The occurrence of actinomycetes in large 

 quantities in stable manures has long been 

 recognized. It is sufficient to mention the 

 early work of Miquel in 1879, of Tsiklinsky 

 in 1899, and of Price-Jones in 1900. Tsi- 

 klinsky isolated two thermophilic actino- 

 mycetes from manures; one was a typical 

 streptomyces and the other a micromono- 

 spora-like organism, which was designated 

 Thcrmoactinomyces vulgaris, since it grew at 

 48 to 68°C, with an optimum at 57°C. Miehe, 

 in his work on the "self-heating of hay," 

 suggested that actinomycetes are, in general, 

 characteristic of decomposing plant residues 

 at high temperatures; hot composts were be- 

 lieved to be the natural substrates for ther- 

 mophilic actinomycetes. Schiitze, Lieske, 

 and others also demonstrated the presence 

 of actinomycetes in decomposing and heat- 

 ing hay and in feces. 



Waksman, Umbreit, and Cordon found an 

 extensive population of facultative thermo- 

 philic actinomycetes in ^'arious soils, espe- 

 cially those treated with stable manures. 

 Composts of horse manure kept at 50 and 

 65°C developed an extensive and character- 

 istic population of these organisms. Six dis- 



