Comparative toxicity of hydrogen peroxide, hydroxyl radicals, and superoxide anion to Escherichia coli

2003 ◽  
Vol 7 (4) ◽  
pp. 961-968 ◽  
Author(s):  
Richard J. Watts ◽  
Diana Washington ◽  
Jimmy Howsawkeng ◽  
Frank J. Loge ◽  
Amy L. Teel
Keyword(s):  
Escherichia Coli ◽  
Hydrogen Peroxide ◽  
Hydroxyl Radicals ◽  
Superoxide Anion ◽  
Comparative Toxicity

scholarly journals Escherichia coli cell inactivation by superoxide anion and hydrogen peroxide.

1981 ◽  
Vol 27 (6) ◽  
pp. 477-485 ◽  
Author(s):  
KEN-ICHI NISHIDA ◽  
MASAMICHI TAKAGI ◽  
KEIJI YANO
Keyword(s):  
Escherichia Coli ◽  
Hydrogen Peroxide ◽  
Superoxide Anion ◽  
Coli Cell ◽  
Cell Inactivation

Oxidation of hydrogen peroxide at the dropping mercury electrode

1984 ◽  
Vol 49 (10) ◽  
pp. 2320-2331 ◽  
Author(s):  
Miroslav Březina ◽  
Martin Wedell
Keyword(s):  
Hydrogen Peroxide ◽  
Superoxide Anion ◽  
Ph Value ◽  
Mercury Electrode ◽  
Electrode Process ◽  
Electrochemical Processes ◽  
Dropping Mercury Electrode ◽  
Oxidation Of Hydrogen ◽  
Decreasing Ph ◽  
Rate Controlling Step

Reduction of oxygen and oxidation of hydrogen peroxide at the dropping mercury electrode are electrochemical processes strongly influenced both by the pH value and the anions in solution. With decreasing pH, both processes become irreversible, especially in the presence of anions with a negative φ2 potential of the diffusion part of the double layer. In the case of irreversible oxygen reduction, the concept that the rate-controlling step of the electrode process is the acceptance of the first electron with the formation of the superoxide anion, O2-, was substantiated. Oxidation of hydrogen peroxide becomes irreversible at a lower pH value than the reduction of oxygen. The slowest, i.e. rate-controlling step of the electrode process in borate buffers at pH 9-10 is the transfer of the second electron, i.e. oxidation of superoxide to oxygen.

scholarly journals Escherichia coli MutM Suppresses Illegitimate Recombination Induced by Oxidative Stress

Genetics ◽  
1999 ◽  
Vol 151 (2) ◽  
pp. 439-446 ◽  
Author(s):  
Masaaki Onda ◽  
Katsuhiro Hanada ◽  
Hirokazu Kawachi ◽  
Hideo Ikeda
Keyword(s):  
Oxidative Stress ◽  
Escherichia Coli ◽  
Hydrogen Peroxide ◽  
Dna Damage ◽  
Double Strand Breaks ◽  
Illegitimate Recombination ◽  
Recombination Analysis ◽  
Wild Type ◽  
Strand Breaks ◽  
In The Wild

Abstract DNA damage by oxidative stress is one of the causes of mutagenesis. However, whether or not DNA damage induces illegitimate recombination has not been determined. To study the effect of oxidative stress on illegitimate recombination, we examined the frequency of λbio transducing phage in the presence of hydrogen peroxide and found that this reagent enhances illegitimate recombination. To clarify the types of illegitimate recombination, we examined the effect of mutations in mutM and related genes on the process. The frequency of λbio transducing phage was 5- to 12-fold higher in the mutM mutant than in the wild type, while the frequency in the mutY and mutT mutants was comparable to that of the wild type. Because 7,8-dihydro-8-oxoguanine (8-oxoG) and formamido pyrimidine (Fapy) lesions can be removed from DNA by MutM protein, these lesions are thought to induce illegitimate recombination. Analysis of recombination junctions showed that the recombination at Hotspot I accounts for 22 or 4% of total λbio transducing phages in the wild type or in the mutM mutant, respectively. The preferential increase of recombination at nonhotspot sites with hydrogen peroxide in the mutM mutant was discussed on the basis of a new model, in which 8-oxoG and/or Fapy residues may introduce double-strand breaks into DNA.

Factors which affect DNA strand breakage in human leukocytes exposed to a tumor promoter, phorbol myristate acetate

1982 ◽  
Vol 60 (11) ◽  
pp. 1359-1366 ◽  
Author(s):  
H. C. Birnboim
Keyword(s):  
Hydrogen Peroxide ◽  
Dna Damage ◽  
Phorbol Myristate Acetate ◽  
Respiratory Burst ◽  
Superoxide Anion ◽  
Tumor Promoter ◽  
Myristate Acetate ◽  
Strand Breakage ◽  
Dna Strand ◽  
Dna Strand Breakage

We have recently reported that phorbol myristate acetate (PMA) induces extensive DNA strand break damage in human peripheral blood leukocytes. The mechanism of action involves superoxide anion and hydrogen peroxide which are generated by phagocytes during the "respiratory burst." In this report, we describe the effect of various inhibitors and scavengers on PMA-induced DNA damage. Azide and cyanide greatly increased the level of damage; sulfhydryl compounds (glutathione, cysteine, and cysteamine) and ascorbate markedly decreased the level of damage. Hydroxyl radical scavengers such as dimethyl sulfoxide (DMSO) and glycerol also decreased the level of damage but apparently did so by inhibiting the respiratory burst. Diethyldithiocarbamate (DDC) increased the level of DNA damage at low concentrations (<1 mM), but decreased DNA damage at ≥1 mM. The results are consistent with a mechanism involving superoxide anion and hydrogen peroxide, but the precise reaction (free radical or enzymatic) responsible for DNA strand breakage has not been determined. The PMA-stimulated phagocyte is an interesting model system for looking at "active oxygen" mediated DNA damage and factors which influence it.

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