A 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. / Master of Science
| Identifer | oai:union.ndltd.org:VTETD/oai:vtechworks.lib.vt.edu:10919/45965 |
| Date | 21 November 2012 |
| Creators | Vercellone, Pamela Ann |
| Contributors | Microbiology, Krieg, Noel R., Smibert, Robert M., Gregory, Eugene M. |
| Publisher | Virginia Tech |
| Source Sets | Virginia Tech Theses and Dissertation |
| Language | English |
| Detected Language | English |
| Type | Thesis, Text |
| Format | ix, 70 leaves, BTD, application/pdf, application/pdf |
| Rights | In Copyright, http://rightsstatements.org/vocab/InC/1.0/ |
| Relation | OCLC# 19611406, LD5655.V855_1988.V473.pdf |
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