Pyruvate relieves the necessity of high induction levels of catalase and enables Campylobacter jejuni to grow under fully aerobic conditions

Aims:  Several cases of campylobacteriosis reported worldwide seemingly conflict with the strict growth requirements and sensitivity to environmental stress of Campylobacter jejuni. In this study, the need for a micro‐aerobic environment dissolved oxygen tension (DOT): 0·1–90%; 100% air saturation)] and the adaptive responses to oxygen stress were studied. Methods and Results:  The growth of C. jejuni in continuous culture was assessed under different DOT in the presence or absence of pyruvate. In a medium without pyruvate, continuous cultures of C. jejuni showed typically micro‐aerobic behaviour and cells were unable to grow under fully aerobic conditions. However in the presence of pyruvate (25 mmol l^?1), continuous cultures of C. jejuni were able to grow in a broad DOT range, varying from 0·1% to at least 90%, and the catalase activity was decreased. Conclusions:  Addition of pyruvate results in the decrease in the concentration of hydrogen peroxide, which enables C. jejuni to grow aerobically. Significance and Impact of the Study:  New information on the oxidative physiology of C. jejuni and its ability to grow aerobically in media supplemented with pyruvate is presented.