Fatty Acid Degradation in Escherichia Coli and Salmonella Enterica Serovar Typhimurium

Wild type strains of S. enterica grow on decanoic acid whereas wild type E. coli strains cannot. Mutant strains (fadR) of both organisms are readily isolated in which the genes (fad) of fatty acid degradation are expressed constitutively. The S. enterica fadR strains grow more rapidly than the wild type strains on decanoic acid and also grow well on octanoic and hexanoic acids. In contrast, Escherichia coli fadR strains grow well on decanoic acid, but grow only exceedingly slowly on octanoic acid and fail to grow at all on hexanoic acid. This difference in growth was partly attributed to S. enterica having higher cytosolic levels of the inducing ligand, fatty acyl-CoAs. The most striking results were the differences in the compositions of CoA metabolites of strains grown with octanoic acid or oleic acid. S. enterica cleanly converted all of the acid to acetyl-CoA whereas E. coli accumulated high levels of intermediate chain length products. Exchanging genes between the two organisms showed that the S. enterica FadE and FadBA enzymes were responsible for the greater efficiency of beta-oxidation.

Name thesis:degree_name

Ph.D.

Level thesis:degree_level

Dissertation

Discipline thesis:degree_discipline

Biochemistry

Grantor

University of Illinois at Urbana-Champaign

Year dc:date

2015

Author dc:creator

• Iram, Surtaj H.

Contributors dc:contributor

• Cronan, John E., Jr

• Biology, Molecular

Language dc:language

eng

Identifier

(MiAaPQ)AAI3199027

OAI identifier oai:identifier

oai:www.ideals.illinois.edu:2142/84817