Action of Certain Bacteria on Uric Acid and Its Substitutes.

Abstract

Morris and Ecker 1 demonstrated that uric acid is destroyed in fecal infusions under conditions that indicate activity of microorganisms. Various bacteria were studied to determine their ability to utilize uric acid. It was found that 6 strains of B. aerogenes grew and utilized uric acid in Koser's medium and that the Bacterium acidi urici (Ulpiani) which was isolated from chicken excreta readily destroyed all the uric acid employed within 30 hours. No uricolytic enzyme, however, was extracted from the organisms.

These observations led to the present study of whether or not the above named organisms are capable of attacking (a) 1-monomethyl uric acid, (b) 3-monomethyl uric acid, (c) 3-9-dimethyl uric acid, (d) 1-3-dimethyl uric acid, (e) 1-3-7-trimethyl uric acid, and a study of the selective destruction of uric acid in a mixture containing the substituted uric acids.

The organisms were implanted in the Benedict and Hitchcock 2 phosphate standard (containing 9 gm. of Na₂HPO₄-12 H₂O; 1 gm. NaH₂PO₄-H₂O; and 200 mg. uric acid per liter). The pH was 7. The substituted uric acids were added in colorimetric equivalents since they gave less color than the uric acid itself. We used for each mg. of uric acid: 1 mg. of 1-monomethyl uric acid, 4 mg. of 3-monomethyl uric acid, 7 mg. of 3-9-dimethyl uric acid, 1.2 mg. of 1-3-dimethyl uric acid, 14 mg. of trimethyl uric acid.

All the culture tubes contained 5 cc. of the media, sterilized at 15 lb. for 15 minutes. Inoculations were made with the Pasteur pipette using 2 drops of a saline suspension made from a 24-hour culture of the organism on slant agar. The organisms were allowed to grow for various periods of time up to 14 days at 37°C. and all determinations were made by the Benedict and Franke 3 method.