Extracellular superoxide provokes glutathione efflux from Escherichia coli cells

Смирнова, Г. В.; Muzyka, Nadezda G.; Ushakov, Vadim Y.; Tyulenev, Aleksey V.; Oktyabrsky, Oleg N.

doi:10.1016/j.resmic.2015.07.007

Cited by 24 publications

(7 citation statements)

References 43 publications

(50 reference statements)

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“…Glutathione was detected in the exometabolome of both strains and previously found also in that of a Pseudovibrio strain (Romano et al, 2014 ). Besides essential intracellular functions, glutathione is a fundamental extracellular protectant for bacteria, in particular as an antioxidant when reactive oxygen species (ROS) are present (Smirnova and Oktyabrsky, 2005 ; Montoya, 2013 ; Smirnova et al, 2015 ). One reason for the presence of glutathione in the exometabolome may be stress caused by the growth conditions and high cell densities and the possible protection against ROS.…”

Section: Discussionmentioning

confidence: 99%

The Exometabolome of Two Model Strains of the Roseobacter Group: A Marketplace of Microbial Metabolites

et al. 2017

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Recent studies applying Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR-MS) showed that the exometabolome of marine bacteria is composed of a surprisingly high molecular diversity. To shed more light on how this diversity is generated we examined the exometabolome of two model strains of the Roseobacter group, Phaeobacter inhibens and Dinoroseobacter shibae, grown on glutamate, glucose, acetate or succinate by FT-ICR-MS. We detected 2,767 and 3,354 molecular formulas in the exometabolome of each strain and 67 and 84 matched genome-predicted metabolites of P. inhibens and D. shibae, respectively. The annotated compounds include late precursors of biosynthetic pathways of vitamins B1, B2, B5, B6, B7, B12, amino acids, quorum sensing-related compounds, indole acetic acid and methyl-(indole-3-yl) acetic acid. Several formulas were also found in phytoplankton blooms. To shed more light on the effects of some of the precursors we supplemented two B1 prototrophic diatoms with the detected precursor of vitamin B1 HET (4-methyl-5-(β-hydroxyethyl)thiazole) and HMP (4-amino-5-hydroxymethyl-2-methylpyrimidine) and found that their growth was stimulated. Our findings indicate that both strains and other bacteria excreting a similar wealth of metabolites may function as important helpers to auxotrophic and prototrophic marine microbes by supplying growth factors and biosynthetic precursors.

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Section: Discussionmentioning

confidence: 99%

The Exometabolome of Two Model Strains of the Roseobacter Group: A Marketplace of Microbial Metabolites

et al. 2017

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“…Colonies were counted over 24hour incubation at 37°C. Changes in the membrane potential (Δψ) were evaluated using ∆ψ-sensitive uorescent dye DiBAC 4 (3) (Wickens et al 2000) as described previously (Smirnova et al 2015). Samples of log-phase cells treated with the protonophore carbonylcyanide m-chlorophenylhydrasone (CCCP, 20 µM) were used as positive control.…”

Section: Study Of Cell Viability and Membrane Potentialmentioning

confidence: 99%

“…Samples of log-phase cells treated with the protonophore carbonylcyanide m-chlorophenylhydrasone (CCCP, 20 µM) were used as positive control. Fluorescent cells were counted using Leica DM2000 microscope as earlier described (Smirnova et al 2015). Total cell number was counted in transmitted light.…”

Section: Study Of Cell Viability and Membrane Potentialmentioning

confidence: 99%

Study of the contribution of active defense mechanisms to ciprofloxacin tolerance in Escherichia coli growing at different rates

Смирнова

Tyulenev

Muzyka

et al. 2022

Antonie van Leeuwenhoek

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Using rpoS, tolC, ompF, and recA knockouts, we investigated their effect on the physiological response and lethality of cipro oxacin in E. coli growing at different rates on glucose, succinate or acetate. We have shown that, regardless of the strain, the degree of changes in respiration, membrane potential, NAD/NADH ratio, ATP and glutathione (GSH) strongly depends on the initial growth rate and the degree of its inhibition. The deletion of the regulator of the general stress response RpoS, although it in uenced the expression of antioxidant genes, did not signi cantly affect the tolerance to cipro oxacin at all growth rates. The mutant lacking TolC, which is a component of many E. coli e ux pumps, showed the same sensitivity to cipro oxacin as the parent. The absence of porin OmpF slowed down the entry of cipro oxacin into cells, prolonged growth and shifted the optimal bactericidal concentration towards higher values. De ciency of RecA, a regulator of the SOS response, dramatically altered the late phase of the SOS response (SOS-dependent cell death), preventing respiratory inhibition and a drop in membrane potential. The recA mutation inverted GSH uxes across the membrane and abolished cipro oxacininduced H 2 S production. At all growth rates, this mutation reduced logCFU ml -1 by about 3 orders of magnitude. All studied mutants showed an inverse linear relationship between logCFU ml -1 and the speci c growth rate, that is, the activity of antibiotic targets. Mutations shifted the plot of this dependence relative to the parental strain according to their signi cance for cipro oxacin tolerance.

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“…The anionic dye DiBAC 4 (3) was used to analyze the bacterial cell membrane potential. 37 For cells with low membrane potential, the negatively charged dye can penetrate more easily, thus increasing the intensity of fluorescence, and vice versa ( Note S1 ). The results showed that the fluorescence intensity of BW/ptqPR + cells was 15.7% lower than that of BW/ptqPR − cells, indicating a higher membrane potential and a higher PMF in BW/ptqPR + cells ( Figure 4 A).…”

Section: Resultsmentioning

confidence: 99%

Scramblase activity of proteorhodopsin confers physiological advantages to Escherichia coli in the absence of light

Fang,

Zhang,

Zhu

et al. 2023

iScience

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Extracellular superoxide provokes glutathione efflux from Escherichia coli cells

Cited by 24 publications

References 43 publications

The Exometabolome of Two Model Strains of the Roseobacter Group: A Marketplace of Microbial Metabolites

The Exometabolome of Two Model Strains of the Roseobacter Group: A Marketplace of Microbial Metabolites

Study of the contribution of active defense mechanisms to ciprofloxacin tolerance in Escherichia coli growing at different rates

Scramblase activity of proteorhodopsin confers physiological advantages to Escherichia coli in the absence of light

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