Waksman 



— 92 — 



Actinomycetes 



those that produce cyhndrical spores do not give rise to any odor. The 

 presence of carbohydrates in the medium favors odor production. The 

 thermophihc actinomycetes are responsible for the more fruity scents, 

 which arise particularly from young cultures. 



RuLLMANN was the first to make a detailed study of the pungent 

 odor produced by certain species of actinomvcetes. The odoriferous 

 substance is soluble in ether (373, 376). 



SO 



Incubation 



Days 



Oensii-t^ o/^ MyctUum 



CO2 EvoLution 



Fig. 20.— Influence of temperature upon growth and carbon dioxide production 

 by actinomycetes Cf^om Jensen, 192). 



Thaysen (417) found that this substance is partly soluble in ethyl 

 alcohol, and he considered it to be an organic amine. In high con- 

 centrations, it had a manurial odor, but in high dilutions, especially in 

 slightly alkaline water, it became markedly "earthy." One strain of 

 an actinomyces was grown in broth, the culture distilled at ordinary 

 pressure and the distillate treated with ether. On removal of ether and 

 dilution of the residual substances 2:10,000,000 in water at pH 7.5-8.0, 

 a typical earthy odor was obtained. When the "odor concentrate" was 



