Effect of Glucose on Urea Decomposition by B. Proteus.

A typical strain of B. proteus vulgaris was grown in sugar free beef infusion broth, 1.0% glucose infusion broth, 0.5% urea infusion broth, and 1.0% glucose, 0.5% urea infusion broth, respectively. Incubation was practiced at 37° C. for 1, 3 and 5 days, at which times the following determinations were made:

a—Titratable acidity or alkalinity expressed as cc. of normal acid or alkali per 100 cc. of media.

b—Hydrogen-ion concentration.

c—Quantitative ammonia expressed as mg. of ammonia nitrogen per 100 cc.

d—Quantitative sugar expressed in percentage.

Results—For simplicity only the maximum readings without respect to days of incubation are here reported.

The reaction of the plain broth became 1.8 cc. alkaline, pH 7.3 to 8.3 and the glucose broth 3.0 cc. acid, pH 7.2 to 5.3. The amount of ammonia produced in the glucose broth was 8.9 mg. as against 36 mg. in the same broth without sugar. The alkalinity of the plain urea broth increased 6.7 cc., pH 7.3 to 9.2, and the ammonia 179.3 mg. The reaction of the glucose urea broth changed 1.5 cc. alkaline, pH 7.2 to 8.0, in contrast to the acidity of the glucose broth but not nearly to the degree of alkalinity manifested by the plain urea broth. Nevertheless 40.1 mg. more ammonia was produced in the glucose urea broth than in the plain urea broth, which is still more significant in view of the fact that the sparing action of glucose for protein is here also undoubtedly operative. Clearly the presence of glucose accelerated the decomposition of the urea.

In the glucose broth the amount of glucose was reduced from 0.999% to 0.604%, while in the glucose urea broth the reduction was from 0.971% to 0.058%. Plainly then the urea in turn accelerated the destruction of the glucose.