ON THE SIGNIFICANCE OF THE VOGES- 

 PROSKAUER REACTION! 



MAX LEVINE 



From the Laboratories of the Engineering Experiment Station and the Department 

 of Bacteriology of the Iowa State College, Ames, Iowa 



Theobald Smith (1895) first called attention to the ratio of 

 the gases evolved in the decomposition of glucose by B. coli 

 and its relatives. He pointed out that whereas B. coli produced 

 twice as much hydrogen as carbon dioxide, equal volumes of 

 these gases were formed by B. aerogenes.^ In consequence of 

 the inaccuracies in the determination of the gases in the Smith 

 tube, the gas ratio has been generally discarded as a differential 

 criterion. However, the comparatively recent work of Harden 

 in England, and particularly that of Rogers and his associates 

 in the Dairy Division of the United States Department of Agri- 

 culture, indicates that the gaseous and other decomposition 

 products of glucose, if accurately determined, are of considerable 

 importance in the differentiation of coli-like bacteria. 



In a careful quantitative study of glucose fermentation. Har- 

 den and Walpole (1905), showed that B. coli evolved carbon 

 dioxide and hydrogen in approximately equal volumes, and not, 

 as had been observed by Smith, in the ratio of 1 to 2. On the 

 other hand, the B. aerogenes formed twice as much carbon dioxide 

 as hj^drogen instead of the equal volumes observed with the 

 Smith tube. They point out that the difference between the 

 gas ratio obtained with the Smith tube and their accurately 

 determined ratio is due to the loss of carbon dioxide in the for- 

 mer case owing to its solubility in the medium. 



1 Presented at the Seventeenth Annual Meeting of the Society of American 

 Bacteriologists, Urbana, Illinois, December 28, 1915. 



* B . aerogenes as employed in this paper, is synonymous with B. lactis aerogenes, 

 i.e., those organisms of MacConkey's type IV (sucrose + , dulcitol — ) which 

 give a positive Voges-Proskauer reaction. 



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