METABOLISM OF ACTINOMYCETES 



39 



Only one ammonium salt was included in table 2 ; the data ob- 

 tained do not tell us much about the change in reaction produced 

 with ammonium sulfate as the only source of nitrogen, since this 

 salt was used by most species to only a very limited extent. 

 This limited utilization of the ammonium salt may possibly be 

 due to the fact that glycerol as a source of carbon is not readily 

 available with this source of nitrogen. The same may hold true 

 about urea. 



Glucose was found to be a superior source of carbon to glycerol 

 for most actinomycetes. This source of carbon was therefore 



TABLE 3 



used (3 per cent) with ammonium sulfate, ammonium carbonate 

 and urea (0.2 per cent each) , as sources of nitrogen. The cultures 

 were incubated at 25° for 24 days. A much better growth was 

 obtained on these nitrogen compounds, in the presence of glucose, 

 than with glycerol. A. madurae, A. bovis, A. bobili, A. reticuli, 

 and A . verne made a scant to fair growth on these nitrogen sources. 

 A. scabies, A. aureus, A. aster oides, A. viridochromogenus and A. 

 violaceus-ruber made a good to very good growth on urea and 

 ammonium carbonate and a fair to good growth on ammonium 

 sulfate. The changes in reaction are recorded in table 3. 



