Type of Document Master's Thesis Author Vercellone, Pamela Ann URN etd-11212012-040236 Title Oxygen toxicity in Campylobacter jejuni :physiological comparison of a microaerophilic wild-type strain with an aerotolerant mutant Degree Master of Science Department Microbiology Advisory Committee
Advisor Name Title Krieg, Noel R. Committee Chair Gregory, Eugene M. Committee Member Smibert, Robert M. Committee Member Keywords
Date of Defense 1988-12-05 Availability restricted Abstract
A comparative study of the microaerophilic Campylobacter jejuni 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 C. jejuni, the level of catalase activity may influence the degree of susceptibility to H2O2 and consequently, the degree of aerotolerance.
Filename Size Approximate Download Time (Hours:Minutes:Seconds)
28.8 Modem 56K Modem ISDN (64 Kb) ISDN (128 Kb) Higher-speed Access LD5655.V855_1988.V473.pdf 3.28 Mb 00:15:12 00:07:49 00:06:50 00:03:25 00:00:17next to an author's name indicates that all files or directories associated with their ETD are accessible from the Virginia Tech campus network only.
If you have questions or technical problems, please Contact DLA.