Accession Number : AD0746193

Title :   Effects of Hyperoxia on Sulfhydryl Concentration of 'Escherichia coli'.

Descriptive Note : Technical rept.,

Corporate Author : MISSOURI UNIV COLUMBIA SPACE SCIENCES RESEARCH CENTER

Personal Author(s) : Stees,Jack L. ; Brown,Olen R.

Report Date : JUL 1972

Pagination or Media Count : 26

Abstract : The concentration of reduced sulfhydryl (SH) in cell-free extracts of Escherichia coli grown with air as the gas phase was 26.8 plus or minus 1.2 mnoles SH/mg soluble protein. Exposure of bacteria to 1 ata of oxygen where growth continued but at a reduced rate, or to 6.2 ata of oxygen where growth was completely stopped, did not result in significant changes in intracellular SH concentration. Cell-free extracts exposed to 1.2 ata of oxygen resulted in SH oxidation at 0.5%/min, compared to 0.75%/min for reduced glutathione at 4.2 ata. Fractionation of cell-free extracts by ultrafiltration indicated that approximately 92% of the measurable SH-groups were protein-related. These data indicate that neither oxidation of intracellular SH, nor the relatively slow oxidation of surface SH-groups is a significant factor in the rapid growth inhibition of E. coli by hyperoxia. Bacterial reversal of possible intracellular SH oxidation during the interval between decompression and extraction was not excluded. (Author)

Descriptors :   (*OXYGEN CONSUMPTION, THIOLS), (*THIOLS, ESCHERICHIA COLI), (*OXYGEN, *ESCHERICHIA COLI), TOXICITY, GROWTH(PHYSIOLOGY), INHIBITION, METABOLISM, LIPIDS, FATTY ACIDS, HIGH PRESSURE, OXIDATION

Subject Categories : Biochemistry
      Stress Physiology

Distribution Statement : APPROVED FOR PUBLIC RELEASE