156 MAX LEVINE 



Walpole (1910) found that in the presence of oxygen B. aero- 

 genes gave a larger yield of acetyl-methyl-carbinol from glucose 

 and that fructose was decomposed in a similar manner. 



Neither acetyl-methyl-carbinol nor butyleneglycol, when mixed 

 with potassium hydroxide give the eosin-like coloration. In 

 the presence of peptone, however, the coloration develops on 

 standing in the case of the carbinol, but not with the glycol. 

 According to Harden (1905) the reaction is due to the further 

 oxidation of the carbinol (CH3CO.CHOH.CH3) to diacetyl 

 (CH3CO.CO.CH3) which reacts with some constituent of the 

 peptone. In a later study Harden and Norris (1911) report 

 that in the presence of strong potassium hydroxide solution 

 diacetyl reacts with proteins to give a pink coloration together 

 with a green fluorescence. With arginine, creatine, dicyanamide 

 and guanidine acetic acid, the pink coloration is also obtained 

 but the fluorescence is absent. The reaction depends on the 

 presence of the group NH:C (NH2) N:HR. The exact signifi- 

 cance of R. has not been determined. 



Among the organisms capable of forming acetyl-methyl- 

 carbinol from carbohydrates may be mentioned, B. aerogenes 

 Escherich, B. cloacae Jordan, B. subtilis Cohn, B. vulgatus Fliigge. 

 Pere obtained volatile substances which reduced Fehling's solu- 

 tion, by the aerobic fermentation of mannitol by B. subtilis 

 and B. vulgatus and of glucose and glycerol by Tyrothrix tenuis. 



CORRELATION OF VOGES-PROSKAUER AND METHYL-RED REACTIONS 



A study of 167 coli-like bacteria obtained from various sources 

 including raw and septic sewage, stock cultures from the Ameri- 

 can Museum of Natural History, and feces of the horse, cow, 

 sheep, hog and man, showed that only those which were alkaline 

 to methyl red (in a medium made up of 0.5 per cent K2 H PO4, 

 peptone and glucose) gave the Voges-Proskauer reaction. Of 

 13 cultures which gave these reactions, 9 were from sewage 

 and 4 from the museum collection. It should be noted that 

 coli-like organisms giving these reactions were not obtained, 

 even in a single instance, from the fecal samples. 



