Relationship of demethylation processes to veratric acid concentration and cell density in cultures of <i>Rhodococcus erythropolis</i>

Paździoch-Czochra, Marzanna

doi:10.1016/s1065-6995(02)00282-2

Cited by 25 publications

(17 citation statements)

References 32 publications

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“…erythropolis cells, described in our earlier papers [17,19], was used. This biological system is sensitive both to an excess and a lack of FA as well as to normal and excited states of this molecule.…”

Section: Discussionmentioning

confidence: 99%

“…Owing to this activation, FA became particularly reactive with vanillic acid and was able to convert it again into veratric acid via the path of non-enzymatic methylation. Thus, while demethylation is connected with the presence of an active form of the enzyme 4-O-demethylase, methylation seems to occur spontaneously using free-radical energy, which activates FA as a donor of a methyl group [19]. …”

Section: Introductionmentioning

confidence: 99%

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Nonlinear changes in the activity of the oxygen-dependent demethylase system in Rhodococcus erythropolis cells in the presence of low and very low doses of formaldehyde

Malarczyk¹,

Paździoch-Czochra²,

Grąz³

et al. 2011

Nonlinear Biomed Phys

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The effect of exogenous, highly diluted formaldehyde on the rate of demethylation/re-methylation of veratric acid by the bacteria Rhodococcus erythropolis was studied using electrophoretic and microscopic techniques. The activity of 4-O-demethylase, responsible for accumulation of vanillic acid, and the levels of veratric and vanillic acids were determined using capillary electrophoresis. Formaldehyde was serially diluted at 1:100 ratios, and the total number of iterations was 20. After incubation of the successive dilutions of formaldehyde with the bacteria, demethylase activity oscillated in a sinusoidal manner. It was established using capillary electrophoresis that methylation of vanillic acid to veratric acid occurred at a double rate, as shown by the doubled fluctuation in the concentration of veratrate. There were also changes in the NADH oxidase activity, which is associated with methylation processes. Microscopic observations revealed the presence of numerous enlarged vacuoles in bacterial cells during the accumulation of large amounts of vanillic acid, and their disappearance together with a decrease in 4-O-demethylase activity. The presented results give evidence for the ability of living cells to detect the presence of submolecular concentrations of biological effectors in their environment and provide a basis for a scientific explanation of the law of hormesis and the therapeutic effect of homeopathic dilutions.

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Section: Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Nonlinear changes in the activity of the oxygen-dependent demethylase system in Rhodococcus erythropolis cells in the presence of low and very low doses of formaldehyde

Malarczyk¹,

Paździoch-Czochra²,

Grąz³

et al. 2011

Nonlinear Biomed Phys

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“…The SOR level measurement was done according to the method for rapid detection of superoxide anion generation in fungal material [38]. The relative level of SOR was estimated spectrophotometrically based on the detection of superoxide-induced formation of formazan from nitrotetrazolium blue (NBT) under alkaline conditions, as described previously [13].…”

Section: Methodsmentioning

confidence: 99%

Effective Stimulation of the Biotechnological Potential of the Medicinal White Rot Fungus: Phellinus pini by Menadione-Mediated Oxidative Stress

Jaszek

Kos

Matuszewska

et al. 2014

Appl Biochem Biotechnol

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The effect of menadione (MQ; 2-methyl-1,4-naphtoquinone), a superoxide-generating agent, on the natural biodegradation system in the medicinal white rot fungus Phellinus pini was determined. While measuring the activities of extracellular manganese-dependent peroxidase (MnP) and intracellular chitinase, it was found that the application of MQ (0.75 mM) distinctly stimulated the activities of these enzymes in comparison to the control values (without MQ). Using the capillary electrophoresis (CE) method, an increase in the extracellular oxalic acid (OXA) concentration was detected during the first days after the addition of MQ. It was observed that the rate of intracellular proteolysis at pH 3.5 evidently decreased under oxidative stress conditions. Contrary to these results, the activities of serine proteases at pH 9.5 measured against fluorogenic peptide substrates distinctly increased in stressed cultures. The MQ treatment also caused an evident increase in the catalase (CAT) activity, as well as the levels of superoxide anion radicals (SORs), formaldehyde (FA), and phenolic compounds (PHC) in the experimental cultures. The results obtained confirm that prooxidants may find application as an effective way to stimulate biotechnological production of MnP and chitinase by white rot fungi.

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“…The measurement of the level of SOR was done according to the method described previously (Paździoch-Czochra et al 2003). The relative level of SOR was measured spectrophotometrically by detection of superoxide-dependent formation of formazone from nitrotetrazolium blue (NBT) in the alkaline conditions.…”

Section: Relative Level Of Superoxide Anion Radicals (Sor)mentioning

confidence: 99%

The response of the Rhizobium leguminosarum bv. trifolii wild-type and exopolysaccharide-deficient mutants to oxidative stress

et al. 2013

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Aims The aim of this study was investigation of the response of R. leguminosarum bv. trifolii wild-type and its two rosR and pssA mutant strains impaired in exopolysaccharide (EPS) synthesis to oxidative stress conditions caused by two prooxidants: a superoxide anion generator-menadione (MQ) and hydrogen peroxide (H 2 O 2 ). Methods The levels of enzymatic (catalase, superoxide dismutase, pectinase and β-glucosidase) and nonenzymatic (superoxide anion generator, formaldehyde, phenolic compounds) biomarkers were monitored using biochemical methods in both the supernatants and rhizobial cells after treatment with 0.3mM MQ and 1.5mM H 2 O 2 . The viability of bacterial cells was estimated using fluorescent dyes and confocal laser scanning microscopy. In addition, the effect of prooxidants on symbiosis of the R. leguminosarum bv. trifolii strains with clover was established. Results The tested stress factors significantly changed enzymatic patterns of the rhizobial strains, and the wildtype strain proved to be more resistant to these prooxidants than both pssA and rosR mutants. Significantly higher activities of both catalase and superoxide dismutase have been detected in these mutants in comparison to the wildtype strain. H 2 O 2 and MQ also increased the levels of pectinase and β-glucosidase activities in the tested strains. Moreover, pre-incubation of R. leguminosarum bv. trifolii strains with the prooxidants negatively affected the viability of bacterial cells and the number of nodules elicited on clover plants. Conclusions EPS produced in large amounts by R. leguminosarum bv. trifolii plays a significant protective role as a barrier against oxidative stress factors and during symbiotic interactions with clover plants.

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Relationship of demethylation processes to veratric acid concentration and cell density in cultures of Rhodococcus erythropolis

Cited by 25 publications

References 32 publications

Nonlinear changes in the activity of the oxygen-dependent demethylase system in Rhodococcus erythropolis cells in the presence of low and very low doses of formaldehyde

Nonlinear changes in the activity of the oxygen-dependent demethylase system in Rhodococcus erythropolis cells in the presence of low and very low doses of formaldehyde

Effective Stimulation of the Biotechnological Potential of the Medicinal White Rot Fungus: Phellinus pini by Menadione-Mediated Oxidative Stress

The response of the Rhizobium leguminosarum bv. trifolii wild-type and exopolysaccharide-deficient mutants to oxidative stress

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