Action of Hydrogen Peroxide on Degradation of DNA after Irradiation in<i>Escherichia Coli</i>

Keller, K.; Pollard, Ernest C.

doi:10.1080/09553007714550511

Cited by 13 publications

(7 citation statements)

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“…When P. anaerobius VPI 4330-1 was exposed to 20 ,uM hydrogen peroxide in the anaerobic dilution blank solution under anaerobic conditions, more than 90% of the organisms were killed within 2 min. The toxic effect of hydrogen peroxide was completely abolished by catalase (26 jig/ml), 0.5 mM 8-hydroxyquinoline, and 0.1 mM 2,2'-bipyridine. 1,4-Diazabicyclo[2.2.2]octane (20 mM), bilirubin (2 mM), mannitol (100 mM), and SOD (10,ug/ml) had no effect on the toxicity ofhydrogen peroxide.…”

Section: Oxidation Of Cysteine Cysteine (50 Mm)mentioning

confidence: 96%

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Bactericidal effect of cysteine exposed to atmospheric oxygen

Carlsson¹,

Granberg²,

Nyberg³

et al. 1979

Appl Environ Microbiol

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Peptostreptococcus anaerobius VPI 4330-1 was exposed to atmospheric oxygen in a dilution blank (0.2% gelatin, salts, resazurin) solution. The organisms were rapidly killed when the solution contained cysteine. The organisms were effectively protected by catalase and horseradish peroxidase as well as by the metal ion-chelating agents 8-hydroxyquinoline and 2,2'-bipyridine. Superoxide dismutase increased the rate of killing of the organisms, whereas singlet oxygen quenchers and scavengers of hydroxyl free radicals did not protect the organisms from the toxic effect of cysteine. Hydrogen peroxide was formed when cysteine was exposed to oxygen in the dilution blank solution, and the reaction was inhibited by metal ion-chelating agents. The organisms were rapidly killed by 20 ,uM hydrogen peroxide in anaerobic dilution blank solution. The toxic effect of hydrogen peroxide was completely abolished by catalase and metal ion-chelating agents. These results indicated that hydrogen peroxide was formed in the dilution blank solution in a metal ion-catalyzed autoxidation of cysteine and that hydrogen peroxide was toxic to P. anaerobius VPI 4330-1 in a reaction also catalyzed by metal ions. Cysteine may be toxic to or may inhibit growth of Escherichia coli (11, 25, 46), Bacillus subtilis (52), yeasts (7, 33, 36), and fungi (4, 49). Cysteine appears to inhibit growth by two different mechanisms in E. coli. It may interfere with biosynthesis of leucine, isoleucine, threonine, and valine, or it may interact with the function of membrane-bound enzymes (25). The growth-inhibiting effect of cysteine in yeasts has been ascribed to its ability to chelate metal ions necessary for the activities of various enzymes (7, 36). Cysteine is routinely used in many media for the cultivation of anaerobic bacteria (22). In a study on the bactericidal effects of various culture media exposed to atmospheric oxygen (13), it was observed that cysteine was toxic to Peptostreptococcus anaerobius VPI 4330-1. We now report that hydrogen peroxide is formed from cysteine in the presence of oxygen in a metal ion-catalyzed reaction and that hydrogen peroxide is toxic to P. anaerobius VPI 4330-1 in a reaction also catalyzed by metal ions. MATERIALS AND METHODS Microorganisms. P. anaerobius strain VPI 4330-1 (ATCC 27337) was used as the test strain (23). It was kept on blood agar plates at 4°C under strictly anaerobic conditions in an anaerobic box with an atmosphere of 10% H2 and 5% CO2 in nitrogen (54).

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Section: Oxidation Of Cysteine Cysteine (50 Mm)mentioning

confidence: 96%

“…The site of damage of bacteria injured by hydrogen peroxide has not been established. In E. coli, paralysis of the respiratory chain (18), deoxyribonucleic acid (DNA) strand breakage (44), and DNA degradation (26) have been reported. Such changes are also induced, however, in cells exposed to various forms of physical and chemical stresses (6,42).…”

Section: -mentioning

confidence: 99%

Bactericidal effect of cysteine exposed to atmospheric oxygen

Carlsson¹,

Granberg²,

Nyberg³

et al. 1979

Appl Environ Microbiol

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“…FISH with direct fluorescently labeled probes often shows too low signal-tonoise ratios for small cells from oligotrophic environments to be detected by flow cytometers [17]. CARD-FISH [18] provides signals that are 26 to 41-fold brighter than FISH with mono-labeled probes [19], but involves a radical reaction with hydrogen peroxide which can damage the cellular DNA [20]. A radical-free alternative to CARD-FISH is the two-step hybridization chain reaction (HCR)-FISH which was applied to bacteria by Yamaguchi et al [21].…”

Section: Introductionmentioning

confidence: 99%

A pipeline for targeted metagenomics of environmental bacteria

et al. 2020

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Background: Metagenomics and single cell genomics provide a window into the genetic repertoire of yet uncultivated microorganisms, but both methods are usually taxonomically untargeted. The combination of fluorescence in situ hybridization (FISH) and fluorescence activated cell sorting (FACS) has the potential to enrich taxonomically well-defined clades for genomic analyses. Methods: Cells hybridized with a taxon-specific FISH probe are enriched based on their fluorescence signal via flow cytometric cell sorting. A recently developed FISH procedure, the hybridization chain reaction (HCR)-FISH, provides the high signal intensities required for flow cytometric sorting while maintaining the integrity of the cellular DNA for subsequent genome sequencing. Sorted cells are subjected to shotgun sequencing, resulting in targeted metagenomes of low diversity. Results: Pure cultures of different taxonomic groups were used to (1) adapt and optimize the HCR-FISH protocol and (2) assess the effects of various cell fixation methods on both the signal intensity for cell sorting and the quality of subsequent genome amplification and sequencing. Best results were obtained for ethanol-fixed cells in terms of both HCR-FISH signal intensity and genome assembly quality. Our newly developed pipeline was successfully applied to a marine plankton sample from the North Sea yielding good quality metagenome assembled genomes from a yet uncultivated flavobacterial clade. Conclusions: With the developed pipeline, targeted metagenomes at various taxonomic levels can be efficiently retrieved from environmental samples. The resulting metagenome assembled genomes allow for the description of yet uncharacterized microbial clades.

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“…Similarities observed in the responses elicited by these treatments support the thesis that common processes, potentially mediated by ROS, may underlie both treatment regimens. It is our hypothesis that CT, like PDT, is effective in cancer treatment through eliciting a sequela of effects including direct cell killing, ROS generation, vascular damage, inducing inflammatory responses and the stimulation of nonspecific or specific immune effector cells ( 34–47 ). The process of catalytic oxygenation of ascorbate by cobalt (II) octa-4,5-carboxyphthalocyanine (PcCo) is shown in Scheme 1 ( 48 ).…”

Section: Introductionmentioning

confidence: 99%

Catalytic Therapy of Cancer with Ascorbate and Extracts of Medicinal Herbs

Rozanova

Zhang

Heck

2007

Evidence-Based Complementary and Alternative Medicine

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Catalytic therapy (CT) is a cancer treatment modality based on the generation of reactive oxygen species (ROS) using a combination of substrate molecules and a catalyst. The most frequently used substrate/catalyst pair is ascorbate/Co phthalocyanine (PcCo). In the present work, herb extracts containing pigments have been studied as a catalyst in place of PcCo. Extracts from herbs are expected to have efficiency comparable with that of phthalocyanines but as natural products, to exhibit fewer side effects. The present studies demonstrate that a combined use of ascorbate and herbal extracts results in ROS production and a significant decrease in the number of cancer cells after a single in vitro treatment. Treatment with ascorbate in conjunction with extracts prepared from several medicinal herbs stimulated apoptosis and disrupted the cell cycle. The number of cells accumulating in the sub-G0/G1 stage of the cell cycle was increased 2- to 7-fold, and cells in G2/M increased 1.5- to 20-fold, indicating that the treatment protocol was highly effective in suppressing DNA synthesis and potentially reflecting DNA damage in the tumor cells. In addition, 20–40% of the cells underwent apoptosis within 24 h of completing treatment. Our results suggest that herbal extracts can function as CT catalysts in the treatment of cancer.

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Action of Hydrogen Peroxide on Degradation of DNA after Irradiation inEscherichia Coli

Cited by 13 publications

References 7 publications

Bactericidal effect of cysteine exposed to atmospheric oxygen

Bactericidal effect of cysteine exposed to atmospheric oxygen

A pipeline for targeted metagenomics of environmental bacteria

Catalytic Therapy of Cancer with Ascorbate and Extracts of Medicinal Herbs

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