Vercellone, Pamela Ann2014-03-142014-03-141988-12-05etd-11212012-040236http://hdl.handle.net/10919/45965A comparative study of the microaerophilic <u>Campylobacter jejuni</u> strain H840 with an aerotolerant mutant, MC711-01, revealed that catalase and, to a lesser extent, SOD activity is correlated with the aerotolerance and enhanced resistance of MC7ll-0l to H₂O₂. When cells were cultured under 6% oxygen, the specific activity of catalase was significantly higher in crude extracts of MC711-01 than of H840. The catalase activity of MC711-01 more than doubled when cells were cultured under 21% oxygen, and this activity was 2.6 times greater than that of H84O; no corresponding increase was observed in strain H840. There was no significant difference in the mean SOD activity of the two strains when cultured under 6% oxygen or in H840 cells cultured under either 6% or 21% oxygen; however, the SOD activity of MC711-01 increased 1.5 times when cells were cultured under 21% oxygen. Survival studies revealed that MC711-01 was significantly more E resistant to H₂O₂ when cultured under either 6% or 21% oxygen. However, both MC711-01 and H84O were more susceptible to H₂O₂ when grown under 21% oxygen, indicating that both strains might be more highly stressed when the cells are grown at this oxygen tension. The present study suggests that in <u>C. jejuni</u>, the level of catalase activity may influence the degree of susceptibility to H₂O₂ and consequently, the degree of aerotolerance.ix, 70 leavesBTDapplication/pdfenIn CopyrightLD5655.V855 1988.V473CampylobacterOxygen -- ToxicologySpirillaceaeThesishttp://scholar.lib.vt.edu/theses/available/etd-11212012-040236/