Oxygen toxicity in Campylobacter jejuni: physiological comparison of a microaerophilic wild-type strain with an aerotolerant mutant

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.

Name thesis:degree_name

Master of Science

Level thesis:degree_level

masters

Discipline thesis:degree_discipline

Microbiology

Department dc:contributor.department

Microbiology

Grantor dc:publisher

Virginia Tech

Year dc:date.issued

1988

Author dc:creator

• Vercellone, Pamela Ann

Chair dc:contributor.committeechair

• Krieg, Noel R.

Committee members dc:contributor.committeemember

• Smibert, Robert M.
• Gregory, Eugene M.

Statement dc:rights

• In Copyright

Licence dc:rights.uri

• http://rightsstatements.org/vocab/InC/1.0/

Language dc:language.iso

en

Dc Identifier Other

etd-11212012-040236

OAI identifier oai:identifier

oai:vtechworks.lib.vt.edu:10919/45965