Studies of Respiration in H. pylori

In the procedures described here, respiratory metabolism is estimated by direct determination of oxygen uptake, measured as a reduction in the dissolved oxygen tension (DOT) of cell suspensions or extracts. Continuous monitoring of DOT is achieved using a Clark-type oxygen electrode linked to a chart recorder. The volume of cell suspension required is of the order of 1 mL (0.5-1 mg cell protein mL) and the method is sufficiently sensitive to detect the consumption of a few nmol oxygen per mL. This sensitivity and the rapidity with which measurements may be made makes the technique particularly useful for the study of organisms, such as Helicobacter pylori, which give relatively poor growth yields and which, being microaerobic, are likely to be more susceptible to prolonged experimental procedures at high oxygen tensions.