THE CLASSIFICATION OF THE ACIDURIC BACTERIA 



ALFRED H. RAHE 



From the Department of Hygiene, Cornell University Medical College 



Received for publication September 10, 1917 



The proliferation of the aciduric bacteria apparently depends 

 upon the almost exclusive utilization of carbohydrates or 

 carbohydrate-like substances. The corollary of this property, 

 that is, the ability to survive in the presence of considerable 

 amounts of acid is made use of in their isolation. The titles 

 applied to this group have varied with the authors who have 

 studied it. The term ''Lactic acid bacteria" is certainly too. 

 broad, since its use would force the inclusion of organisms that 

 are of an entirely different type, such as B. colt. "Bulgaricus" 

 and "Caucasicum" are unsuitable terms because these bacilli 

 are neither the most frequently occurring nor the typical mem- 

 bers of this group. "Acidophilus," while more nearly appro- 

 priate, is still inexact, since this bacillus is characterized by its 

 acid resisting rather than by its acid "loving" properties. Upon 

 the whole, the word "aciduric," adopted by Kendall (1910) 

 appears to be the most fitting term under which to group these 

 organisms.^ 



The distribution of the aciduric bacteria calls for no comment, 

 their ubiquity as a group has long been known. The distri- 

 bution of individual members, however, is less well understood. 

 In 1909 Heinemann and Hefferan published a paper in which it 

 was stated that B. acidophilus and B. hulg^ricus were identical. 

 It seemed to the writer that much of the work on this subject, 

 both preceding and following that of these authors, was not as 

 convincing as might be, owing to the failure of practically all 



1 Distaso (Cent. f. Bakt. Orig. 1911, 59, 48) employed the term acid-tolerant. 



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