15 



correlates very well with the Voges Proskauer test and will be considered 

 more in detail in the following pages. 



Uric Acid Test. Koser, in studying the utilization of nitrogen from 

 various sources, observed that some members of the colon group (Bact. aer- 

 ogenes) can utilize nitrogen from uric acid, whereas others (Bact. coli] 

 can not. He also showed this characteristic to be correlated with the 

 methyl red and Voges Proskauer reaction. 



Resume. The colon group obviously includes many varieties and 

 species of bacteria. The monosaccharids and the disaccharid lactose are 

 always fermented with acid and gas formation; nitrates are reduced and 

 milk is acidified and coagulated; but with respect to other tests there is 

 considerable variation within the group. 



TABLE V. CHARACTERISTICS OF 333 STRAINS OF COLON GROUP FROM 

 SOIL, FECES AND SEWAGE. 



'Acid and gas formation observed. 



In general the reactions of the organisms isolated from the soil are 

 quite different from those obtained from various animal feces (horse, sheep, 

 pig, cow, and man) and sewage. In Table V. and figure 1 are shown the 

 frequency of the various reactions. 



