Growth rates and end-point yields of H. pylori grown in EMF12 medium with various purine sources.

aDoubling times were calculated using at least five data points taken during exponential growth. Values are the mean ± SD of three or more independent experiments. Doubling times in guanine, xanthine and guanosine were significantly longer than for hypoxanthine, inosine, or adenosine (student's t-test, P600 values were not significantly different from one another.bNG = No growth observed after 36 hours.