1915] Edgar G. Miller, Jr. 195 



137. Observations on the metabolism of Bacillus vulgaris. 

 I. J. Kligler. {Dep't of Public Health, Amer. Museum of Natural 

 Hist., N. Y. City. ) B. vulgaris, ever since its discovery by Hauser, 

 has been associated with putrefaction. Hauser, Tisier and Metchni- 

 koff attribute to it putrefactive properties. Metchnikoff believes it 

 is the etiologic factor in Infant diarrhea. Bienentock, and more re- 

 cently Rettger, deny, however, that this organism has the power of 

 initiating real putrefactive processes. Aside from these conflicting 

 results, comparatively little is known of the metabolism of B. vul- 

 garis and the various conditions influencing it. 



Glenn observed that glucose exerts an inhibiting influence on 

 liquefaction, and attributed the Inhibition to the acid produced. De- 

 tailed experiments, though as yet incomplete, indicate that, while the 

 acid does inhibit the action of the liquefying enzyme, in the carbo- 

 hydrate medium it is really the sugar that is directly responsible for 

 the absence of liquefaction. The sugar has a decided sparing effect 

 on the nitrogenous metabolism. The liquefying enzyme is either 

 not secreted during the early stages of the carbohydrate metabolism 

 or eise must be inactivated in some way by the acid. If the acid 

 produced by the organism in a i percent sugar-gelatin sol. is neutral- 

 ized, the medium shaken with toluene to kill the bacteria, and the tubes 

 incubated, no liquefaction is obtained. This test was made with a 

 number of strains after growing them for about three weeks on the 

 sugar medium, which was thus rendered highly acid (5-6 percent 

 N acid). Further evidence of the sparing action of the sugar is 

 obtained from the end-products in a parallel series of gelatin with, 

 and without, sugar. The former gave high acidity, no odor, and 

 slight amounts of indol and ammonia; while the latter gave slight 

 acid reaction, marked f ecal odor, with large amounts of ammonia and 

 indol. The enzyme itself is active both in weak alkaline and acid 

 Solutions ( — I percent N NaOH; -|- 2 percent A^ HCl), but is in- 

 hibited by higher concentrations. 



The oxygen relation of the organism is very interesting. It is 

 generally supposed to be a facultative anerobe. Preliminary experi- 

 ments indicate, however, that only in the presence of a utilizable 

 sugar can it grow in the absence of oxygen. The sugar molecule 

 apparently supplies the oxygen. In the absence of sugar, when 

 the protein has to be utilized for nutrition, oxygen in an available 



