BACILLUS-COLI-LlKE BACTERIA FROM FECES AND SEWAGE 



19 



One of the Voges-Proskauer-positive strains does not attack 

 glycerol. This is probably B. cloacae. Those Voges-Proskauer-posi- 

 tive organisms which do ferment glycerol, generally form much more 

 acid than the Voges-Proskauer-negative fermenting strains. The mean 

 for the Voges-Proskauer-negative organisms coincides with the. mode 

 at 0.70% normal. The Voges-Proskauer-positive organisms have a 

 mode at 1.50%, with a mean,at 1.28% normal acid. 



TABLE 8 



RELATION OF SOURCE, MACCONKEY TYPE, AND VOGES-PROSKAUER REACTION TO ACID-PRODUCTION 



IN GLYCEROL 



D. DULCITOL 



In Table 9 is indicated the relation of the MacConkey types, the 

 source, and the Voges-Proskauer reaction to acid-production in dul- 

 citol. 



MacConkey Types I and IV do not form acid from dulcitol. Types 

 II and III produce about equal quantities, 0.88% and 0.81% normal 

 acid respectively, but Type II shows a greater variability. 



The sheep, pig, human, and horse strains attack dulcitol more 

 vigorously than do the organisms from the cow. The averages are, 



