THE CLASSIFICATION OF THE ACIDURIC BACTERIA

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. coli. "Bulgaricus" and "Caucasicum" are unsuitable terms because these bacilli are neither the most frequently occurring nor the typical members of this group. "Acidophilus," while more nearly appropriate, 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 distribution 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. bulgaricus 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