Effects of Hyperoxia on Composition and Rate of Synthesis of Fatty Acids in Escherichia coli.
Abstract
Growth and fatty acid synthesis in Escherichia coli were inhibited by oxygen at partial pressures above one atmosphere, and were prevented by exposure to oxygen at 4.2 atmospheres on membranes incubated on a minimal medium. Growth and fatty acid synthesis returned to control rates when cells were removed from hyperoxia to air. The spectrum of fatty acids produced was unchanged by oxygen at pressures which reduced the rate of synthesis. In situ fatty acids were stable to oxygen at pressures which prevented growth and synthesis. Reinitiation of synthesis following complete inhibition in hyperoxia occurred without production of aberrant fatty acids. Fatty acid synthetase specific activity was virtually unchanged, compared to air controls, in cells exposed either to 3.2 or to 15.2 atmospheres of oxygen. The spectrum of fatty acids synthesized by cell-free extracts during incubation in 4.2 atmospheres of oxygen was not different from air incubated controls. Synthetase assays included added NADPH, acyl carrier protein, mercaptoethanol and malonyl coenzyme A; hence, only damage, other than reversible sulfhydryl oxidation, to the apoenzymes of synthetase was ruled out. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Jan 01, 1971
- Accession Number
- AD0717673
Entities
People
- Harvey F. Howitt
- Jack L. Stees
- Olen R. Brown
- Wesley S. Platner
Organizations
- University of Missouri