Publications by authors named "Zuzana Rybkova"

8 Publications

  • Page 1 of 1

Sulfated Metabolites of Luteolin, Myricetin, and Ampelopsin: Chemoenzymatic Preparation and Biophysical Properties.

J Agric Food Chem 2020 Oct 23;68(40):11197-11206. Epub 2020 Sep 23.

Institute of Microbiology of the Czech Academy of Sciences, Vídeňská 1083, CZ 142 20 Prague, Czech Republic.

Authentic standards of food flavonoids are important for human metabolic studies. Their isolation from biological materials is impracticable; however, they can be prepared . Twelve sulfated metabolites of luteolin, myricetin, and ampelopsin were obtained with arylsulfotransferase from and fully characterized by high-performance liquid chromatography, MS, and NMR. The compounds were tested for their ability to scavenge 1,1-diphenyl-2-picrylhydrazyl, 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid), and ,-dimethyl--phenylenediamine radicals, to reduce ferric ions and Folin-Ciocalteu reagent, and to inhibit -butyl hydroperoxide-induced lipid peroxidation of rat liver microsomes. The activity differed considerably even between monosulfate isomers. The parent compounds and myricetin-3'--sulfate were the most active while other compounds displayed significantly lower activity, particularly luteolin sulfates. No mutagenic activity of the parent compounds and their main metabolites was observed; only myricetin showed minor pro-mutagenicity. The prepared sulfated metabolites are now available as authentic standards for future and metabolic studies.
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http://dx.doi.org/10.1021/acs.jafc.0c03997DOI Listing
October 2020

Biodegradation of Reactive Orange 16 azo dye by simultaneous action of Pleurotus ostreatus and the yeast Candida zeylanoides.

Folia Microbiol (Praha) 2020 Aug 22;65(4):629-638. Epub 2020 Jan 22.

Department of Biology and Ecology, Faculty of Science, University of Ostrava, Chittussiho 10, 710 00, Slezská Ostrava, Czech Republic.

The purpose was to investigate a simultaneous biodegradation of the recalcitrant monoazo dye Reactive Orange 16 (RO16) in a mixed culture consisting of a biofilm of Pleurotus ostreatus-colonizing polyamide carrier and a suspension of the yeast Candida zeylanoides to see their biological interactions and possible synergistic action during degradation. Decolorization in the mixed culture was more effective than in the fungal monoculture, the respective decolorizations reaching 87.5% and 70% on day 11. The proliferation of yeast was reduced compared with the C. zeylanoides monoculture but enabled the yeast to participate in decolorization. The interaction of P. ostreatus with the yeast resulted in a gradual decrease of fungal manganese-dependent peroxidase (MnP) and laccase activities. Gas chromatography-mass spectrometry (GC-MS) analysis of the degradation products brought evidence that P. ostreatus split the dye molecule asymmetrically to provide 4-(ethenylsulfonyl) benzene whose concentration was much decreased in the mixed culture suggesting its increased metabolization in the presence of the yeast. In contrast, C. zeylanoides split the azo bond symmetrically producing the metabolites 4-(ethenylsulfonyl) aniline and α-hydroxybenzenepropanoic acid. Those metabolites were rapidly degraded in the mixed culture. A novel aspect is represented by the evidence of a mutual cooperative action of the fungal and yeast microorganisms in the mixed culture resulting in rapid decolorization and degradation of the dye.
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http://dx.doi.org/10.1007/s12223-019-00767-3DOI Listing
August 2020

Biocompatible Polymer Materials with Antimicrobial Properties for Preparation of Stents.

Nanomaterials (Basel) 2019 Oct 31;9(11). Epub 2019 Oct 31.

Nanotechnology Centre, VŠB-Technical University of Ostrava, 17. listopadu 15, 708 00 Ostrava-Poruba, Czech Republic.

Biodegradable polymers are promising materials for use in medical applications such as stents. Their properties are comparable to commercially available resistant metal and polymeric stents, which have several major problems, such as stent migration and stent clogging due to microbial biofilm. Consequently, conventional stents have to be removed operatively from the patient's body, which presents a number of complications and can also endanger the patient's life. Biodegradable stents disintegrate into basic substances that decompose in the human body, and no surgery is required. This review focuses on the specific use of stents in the human body, the problems of microbial biofilm, and possibilities of preventing microbial growth by modifying polymers with antimicrobial agents.
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http://dx.doi.org/10.3390/nano9111548DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6915381PMC
October 2019

Antimicrobial Synergistic Effect Between Ag and Zn in Ag-ZnO·SiO Silicate Composite with High Specific Surface Area.

Nanomaterials (Basel) 2019 Sep 5;9(9). Epub 2019 Sep 5.

Nanotechnology Centre, VSB-Technical University of Ostrava, 17. listopadu 15/2172, 708 33 Ostrava, Czech Republic.

Antimicrobial materials are widely used for inhibition of microorganisms in the environment. It has been established that bacterial growth can be restrained by silver nanoparticles. Combining these with other antimicrobial agents, such as ZnO, may increase the antimicrobial activity and the use of carrier substrate makes the material easier to handle. In the paper, we present an antimicrobial nanocomposite based on silver nanoparticles nucleated in general silicate nanostructure ZnO·SiO. First, we prepared the silicate fine net nanostructure ZnO·SiO with zinc content up to 30 wt% by precipitation of sodium water glass in zinc acetate solution. Silver nanoparticles were then formed within the material by photoreduction of AgNO on photoactive ZnO. This resulted into an Ag-ZnO·SiO composite with silica gel-like morphology and the specific surface area of 250 m/g. The composite, alongside with pure AgNO and clear ZnO·SiO, were successfully tested for antimicrobial activity on both gram-positive and gram-negative bacterial strains and yeast . With respect to the silver content, the minimal inhibition concentration of Ag-ZnO·SiO was worse than AgNO only for gram-negative strains. Moreover, we found a positive synergistic antimicrobial effect between Ag and Zn agents. These properties create an efficient and easily applicable antimicrobial material in the form of powder.
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http://dx.doi.org/10.3390/nano9091265DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6781028PMC
September 2019

Polylactide Composites Suitable for Medical Devices.

J Nanosci Nanotechnol 2019 May;19(5):2506-2513

Nanotechnology Centre, VŠB - Technical University of Ostrava, 17. listopadu 15, 708 33 Ostrava-Poruba, Czech Republic.

Biodegradable polymeric materials with antimicrobial surfaces could be a suitable alternative for production of medical devices, especially if they are prepared in form of composites containing functional matter. Their greatest advantage is that they do not need to be removed from patient's body and simultaneously they can prevent growth of biofilm. In this work, polymeric films of polylactide acid with biosynthetically prepared silver nanoparticles, commercial multiwall carbon nanotubes and organovermiculite with hexadecyltrimethylammonium bromide in various concentrations were prepared to get polylactide composite with antibacterial properties. The dispersibility of filler in matrix was one of the key issues to be controlled in nanocomposite. Using several analytical techniques and observing morphology of prepared composite it was found that best results provide organovermiculite filler. For the tests of functionality antimicrobial tests were performed.
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http://dx.doi.org/10.1166/jnn.2019.15871DOI Listing
May 2019

Toxicity and mutagenicity of low-metallic automotive brake pad materials.

Ecotoxicol Environ Saf 2016 Sep 13;131:37-44. Epub 2016 May 13.

VŠB - Technical University of Ostrava, Nanotechnology Centre, 17. listopadu 15, 708 33 Ostrava, Czech Republic; Southern Illinois University Carbondale, Department of Mechanical Engineering and Energy Processes, Carbondale, IL 62901-4343, USA.

Organic friction materials are standardly used in brakes of small planes, railroad vehicles, trucks and passenger cars. The growing transportation sector requires a better understanding of the negative impact related to the release of potentially hazardous materials into the environment. This includes brakes which can release enormous quantities of wear particulates. This paper addresses in vitro detection of toxic and mutagenic potency of one model and two commercially available low-metallic automotive brake pads used in passenger cars sold in the EU market. The model pad made in the laboratory was also subjected to a standardized brake dynamometer test and the generated non-airborne wear particles were also investigated. Qualitative "organic composition" was determined by GC/MS screening of dichloromethane extracts. Acute toxicity and mutagenicity of four investigated sample types were assessed in vitro by bioluminescence assay using marine bacteria Vibrio fischeri and by two bacterial bioassays i) Ames test on Salmonella typhimurium His(-) and ii) SOS Chromotest using Escherichia coli PQ37 strain. Screening of organic composition revealed a high variety of organic compounds present in the initial brake pads and also in the generated non-airborne wear debris. Several detected compounds are classified by IARC as possibly carcinogenic to humans, e. g. benzene derivatives. Acute toxicity bioassay revealed a response of bacterial cells after exposure to all samples used. Phenolic resin and wear debris were found to be acutely toxic; however in term of mutagenicity the response was negative. All non-friction exposed brake pad samples (a model pad and two commercial pad samples) were mutagenic with metabolic activation in vitro.
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http://dx.doi.org/10.1016/j.ecoenv.2016.05.003DOI Listing
September 2016

(Anti)mutagenic and immunomodulatory properties of quercetin glycosides.

J Sci Food Agric 2016 Mar 29;96(5):1492-9. Epub 2015 May 29.

Institute of Microbiology, Czech Academy of Sciences, Vídeňská 1083, CZ-142 20, Prague 4, Czech Republic.

Background: Quercetin-3-O-β-D-glucopyranoside (isoquercitrin) and quercetin-3-O-rutinoside (rutin) are common components of a normal human diet and are increasingly used in food supplements. Here their effect on mutagenesis and immunity is shown.

Results: The in vitro (anti)mutagenic potential was compared with that of quercetin using the Ames test in Salmonella typhimurium His(-) strains TA100, TA98 and TA102. Isoquercitrin only slightly increased the number of revertants, while rutin was totally non-mutagenic. On the other hand, all compounds displayed dose-dependent protective activity against H2O2 - and tert-butyl hydroperoxide-induced oxidative damage to the TA102 strain and at 75 µmol L(-1) inhibited H2O2/Fe(2+)-induced formation of the open circular and linear forms of the DNA plasmid pBSIISK(-). In mice, none of the flavonols (0.86 µmol day(-1), 34 days) induced harmful effects. In immunized animals, all compounds enhanced ex vivo B cell proliferation; quercetin stimulated lymphocyte basal proliferation and increased the number of IgM-producing lymphocytes. Rutin promoted NK cytotoxic activity, supported T cells and enhanced gut epithelium renewal. No effect on IgG-forming cells was found.

Conclusion: Isoquercitrin displayed negligible and rutin no mutagenicity, but both showed significant antimutagenic and DNA-protective effects against oxidative damage. In vivo, they supported the readiness of the immune system for specific humoral immune response.
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http://dx.doi.org/10.1002/jsfa.7251DOI Listing
March 2016

Biodegradation and detoxification potential of rotating biological contactor (RBC) with Irpex lacteus for remediation of dye-containing wastewater.

Water Res 2013 Dec 20;47(19):7143-8. Epub 2013 Oct 20.

Faculty of Science, University of Ostrava, Chittussiho 10, 710 00 Slezská, Ostrava, Czech Republic. Electronic address:

Use of fungal organisms in rotating biological contactors (RBC) for bioremediation of liquid industrial wastes has so far been limited in spite of their significant biodegradation potential. The purpose was to investigate the power of RBC using Irpex lacteus for decolorization and detoxification of industrial dyes and dyeing textile liquors. Recalcitrant dye Methylene Blue (150 mg L(-1)) was decolorized within 70 days, its mutagenicity removed, and the biological toxicity decreased more than 10-fold. I. lacteus biofilm in the RBC completely decolorized within 26 and 47 days dyeing liquors containing disperse or reactive dyes adjusted to pH4.5 and 5-fold diluted with the growth medium, respectively. Their respective biological toxicity values were reduced 10- to 10(4)-fold in dependence of the test used. A battery of toxicity tests comprising Vibrio fisheri, Lemna minor and Sinapis alba was efficient to monitor the toxicity of textile dyes and wastewaters. Strong decolorization and detoxification power of RBC using I. lacteus biofilms was demonstrated.
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http://dx.doi.org/10.1016/j.watres.2013.07.050DOI Listing
December 2013