Journal of Lipid Research, Vol. 12, 692-698, November 1971
Copyright © 1971 by Lipid Research, Inc.

Effects of hyperoxia on composition and rate of synthesis of fatty acids in Escherichia coli

Olen R. Brown , Harvey F. Howitt , Jack L. Stees , and Wesley S. Platner

Space Sciences Research Center, Department of Veterinary Microbiology, and Department of Physiology, University of Missouri, Columbia, Missouri 65201

Growth of and fatty acid synthesis in Escherichia coli were inhibited by oxygen at partial pressures above 1 atm and were prevented by exposure to oxygen at 4.2 atm 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 after complete inhibition in hyperoxia occurred without production of aberrant fatty acids. Fatty acid synthetase specific activity was virtually unchanged, compared with air controls, in cells exposed either to 3.2 or to 15.2 atm of oxygen. The spectrum of fatty acids synthesized by cell-free extracts during incubation in 4.2 atm of oxygen was not different from air-incubated controls. Synthetase assays included added NADPH, acyl carrier protein, mercaptoethanol, and malonyl coenzyme A; hence, damage, other than reversible sulfhydryl oxidation, to the apoenzymes of synthetase was ruled out.

Supplementary key words biosynthesis • lipids • gas-liquid chromatography • oxygen toxicity • hyperbaric oxygen • fatty acid synthetase

Submitted on February 1, 1971
Accepted on June 21, 1971

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