Two urease activities with different pH optima in Campylobacter pylori and similar organisms

The urease activity of Campylobacter pylori was measured over a range of pH values. In a citrate-Hepes system, two peaks of activity were seen, at pH 5 and at pH 8. The former activity was inhibited by phosphate. Gastric campylobacter-like organisms isolated from the stomachs of several mammals resembled C. pylori in possessing two urease activities with different pH optima.