Chapter V 



85 



Metabolism 



of flakes or small colonies. These organisms never produce a diffused 

 type of growth throughout the medium, as do the bacteria. The only 

 reports of causation of turbidity can be traced to some of the so-called 

 bacterial variants. The growth of the actinomycetes can be easily 

 filtered off through paper or with some filter aid, or it can be removed 

 by centrifugation. Those organisms which, like the Microinonosfora, 

 produce only a limited number of spores, grow much better in a sub- 

 merged and aerated state than in stationary culture. 



The amount of growth produced by actinomycetes depends not only 

 on the nature of the organism but also on the nature of the nutrients, 



Days 



Shakzn 

 Stationary 



Fig. 18.— Metabolic changes produced by S. lavendulae in aerated and stationary 

 cultures Qrom Woodruff and Foster, 517). 



their availability, their concentration, and on the environmental factors, 

 such as reaction, buffering of medium, aeration, temperature, stage of 

 growth, and lysis. These factors influence not only the total amount of 

 growth but also the mechanisms of transformation of the constituents 

 of the medium, that is, the physiology of the organisms (Table 11). 

 In general, there is a definite relation between the concentration and 

 availability of the carbon and nitrogen sources in the medium and the 

 amount of cell material synthesized by actinomycetes. This is brought 

 out in Table 12 and in Fig. 18 (517). The efficiency of carbon utiliza- 

 tion is greater in stationary than in submerged cultures. The maximum 

 grpwth is attained, however, in submerged and aerated cultures. The 

 carbon efficiency of S. lavendulae attains 35 per cent in stationary cul- 



