Effects of Hyperoxia on Oxidized and Reduced NAD and NADP Concentrations in Escherichia coli.

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Abstract:

The concentrations of the pyridine nucleotide coenzymes were measured after exposure of Escherichia coli to various partial pressures of oxygen to determine if changes in the intracellular pool were associated with the toxic effects of hyperoxia. In minimal medium with acetate as the sole carbon source at 37 deg. in air, the concentrations of the coenzymes in thousands of moleculesbacterium were NAD, 469 plus or minus 17 NADH, 158 plus or minus 11 NADP, 55 plus or minus 5 and NADPH, 50 plus or minus 8. Oxygen at 1 atmosphere increased the generation time by 33 compared to air and NAD was decreased by 30 the other coenzymes were unchanged. Oxygen at 6 atmospheres was immediately bacteristatic and 2 hours of exposure produced a 62 decrease in NAD again the other coenzymes were unchanged. The reduction in NAD concentration could be rate-limiting for growth and respiration however, NADPH was present in normal concentration in oxygen-inhibited bacteria and should not be limiting for reductive steps in synthesis. Author

Author(s):
Brunker, Robert L. ; Brown, Olen R.
Author Organization(s):
MISSOURI UNIV COLUMBIA
Descriptive Note:
Technical rept. no. 2, Jan 70-31 Mar 71,
Pagination:
0031

Security Markings

DOCUMENT & CONTEXTUAL SUMMARY

Distribution:
Approved For Public Release

RECORD

Collection: TR
Identifying Numbers
Contract/Grant Number(s):
N00014-67-A-0287-0002
Project Number(s):
NR-136-756
 Subject Terms
Communities of Interest:
No COI(s) Identified
Descriptor(s):
(*COENZYMES, *HIGH PRESSURE), (*ESCHERICHIA COLI, COENZYMES), (*OXYGEN, TOXICITY), BACTERIA, STRESS(PHYSIOLOGY), ENZYMES, OXIDOREDUCTASES, PYRIDINES, NUCLEOTIDES, GROWTH(PHYSIOLOGY), INHIBITION, RESPIRATION
Field(s)/Group(s):
Biochemistry, Stress Physiology
Keyword(s):
*HYPEROXIA, *HYPERBARIC OXYGENATION
Report Date:
1971 Apr 01