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.