Chapter V 



METABOLISM OF ACTINOMYCETES-GROWTH 



AND NUTRITION; PRODUCTION OF ODORS 



AND PIGMENTS 



Nutrient Requirements:— Actinomycetes vary greatly in their nu- 

 trient requirements. Some are able to thrive on very simple com- 

 pounds, whereas others grow only on highlv complex organic materials. 

 Moreover, the same organism may be able to adapt itself to a great 

 variety of nutrients, the amount of cell synthesis depending on the 

 availability of the substrate and on the effect upon the growth of 

 the organism of the secondary changes in the medium resulting from 

 the utilization of the particular substrate. 



Beijerinck (28) was the first to point out that certain organisms 

 are capable of deriving their carbon nutrition and energy needs from 

 the simplest compounds found in the atmosphere. Although he desig- 

 nated one particular organism as a bacillus (B. oJigocarhophilus^ , he 

 himself noted: "We also found another, rarer species belonging to the 

 genus Streptothrix Cohn, with corresponding properties." Lantzsch 

 (251) later demonstrated that even the bacillus of Beijerinck was in 

 reality an actinomyces. 



Although Beijerinck doubted the need for S, Mn, and Fe in the 

 medium, he emphasized the importance of N, P, K, and Mg. The 

 medium he used consisted of 0.1 to 1.0 gm KNO3, 0.2 gm K0HPO4, 

 80 mg MgS04.7H,0, 0.5 mg MnS04.4HoO, 0.5 mg FeCU.SHoO per 

 liter of distilled water. When such a medium was inoculated with a 

 small quantity of garden soil, and flasks were plugged with cotton and 

 incubated at 23°-25°C., there appeared "a thin, white or feebly rose- 

 colored, very dr)^ film, difficult to moisten." The medium remained 

 clear. The growth of the film continued for months and resulted in the 

 accumulation of considerable amounts of organic carbon. Beijerinck 

 found that either nitrate or ammonium salt could be used as a source of 

 nitrogen. The carbon was not derived from the COo, but from the 

 volatile carbon compounds of the atmosphere. Beijerinck ascribed to 

 this organism the property of biologic purification of the air. 



Lantzsch (251) differentiated between the nutrition of two variants 

 of the organism: the filamentous or branched form which assimilated 

 CD; the coccus-like or bacillary form, which assimilated aliphatic hydro- 

 carbons. 



