Publications by authors named "Katerina Malachova"

14 Publications

  • Page 1 of 1

Beta-lactam resistance development during the treatment processes of municipal wastewater treatment plants.

Chemosphere 2021 May 3;280:130749. Epub 2021 May 3.

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

This work monitored the effect of a municipal and a village wastewater treatment plant (WWTP) technology on the fate of beta-lactam resistance genes in bacterial populations in different phases of the wastewater treatment process. In case of the municipal WWTP1, the bacteria possessing a high ampicillin resistance (minimal inhibitory concentration (MIC) values of 20 mg/mL) accumulated in the sedimentation tank, which was accompanied with a higher concentration of ampicillin in the wastewater samples (28.09 ng/L) and an increase in the relative abundance of the blaTEM gene in the bacterial population. However, an opposite trend was revealed with the blaNDM-1 gene, making the sedimentation processes of WWTP1 crucial only for the accumulation of the blaTEM gene. Similarly, the comparison with the WWTP2 showed that the accumulation of the ampicillin resistance in bacterial population probably depended on the WWTP technology and wastewater composition. Out of the four tested resistance genes (blaTEM, blaKPC, blaNDM-1, and blaOXA-48), blaTEM and blaNDM-1 genes were the only two detected in this study. According to NGS analysis of bacterial 16 S rRNA gene, Gammaproteobacteria dominated the ampicillin-resistant bacteria of the WWTP sedimentation tanks. Their relative abundance in the bacterial population also increased during the sedimentation processes in WWTP1. It could indicate the role of the bacterial taxon in ampicillin resistance accumulation in this WWTP and show that only 9.29% of the original bacterial population from the nitrification tank is involved in the documented shifts in beta-lactam resistance of the bacterial population.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.chemosphere.2021.130749DOI Listing
May 2021

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.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1021/acs.jafc.0c03997DOI Listing
October 2020

In-Depth Bioinformatic Analyses of Including Human SARS-CoV-2, SARS-CoV, MERS-CoV Viruses Suggest Important Roles of Non-canonical Nucleic Acid Structures in Their Lifecycles.

Front Microbiol 2020 3;11:1583. Epub 2020 Jul 3.

Department of Biology and Ecology, Faculty of Science, University of Ostrava, Ostrava, Czechia.

Non-canonical nucleic acid structures play important roles in the regulation of molecular processes. Considering the importance of the ongoing coronavirus crisis, we decided to evaluate genomes of all coronaviruses sequenced to date (stated more broadly, the order ) to determine if they contain non-canonical nucleic acid structures. We discovered much evidence of putative G-quadruplex sites and even much more of inverted repeats (IRs) loci, which in fact are ubiquitous along the whole genomic sequence and indicate a possible mechanism for genomic RNA packaging. The most notable enrichment of IRs was found inside 5'UTR for IRs of size 12+ nucleotides, and the most notable enrichment of putative quadruplex sites (PQSs) was located before 3'UTR, inside 5'UTR, and before mRNA. This indicates crucial regulatory roles for both IRs and PQSs. Moreover, we found multiple G-quadruplex binding motifs in human proteins having potential for binding of SARS-CoV-2 RNA. Non-canonical nucleic acids structures in and in novel SARS-CoV-2 are therefore promising druggable structures that can be targeted and utilized in the future.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3389/fmicb.2020.01583DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7347907PMC
July 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.
View Article and Find Full Text PDF

Download full-text PDF

Source
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.
View Article and Find Full Text PDF

Download full-text PDF

Source
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.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3390/nano9091265DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6781028PMC
September 2019

Effect of yeasts on biodegradation potential of immobilized cultures of white rot fungi.

Sci Total Environ 2017 Jul 1;589:146-152. Epub 2017 Mar 1.

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

The aim was to investigate the effect of yeast organisms on the degradation process by immobilized cultures of ligninolytic fungi. Immobilization was accomplished by 7-day colonization of polyamide mesh with mycelial fragments. Irpex lacteus decolorized >90% of the initial concentration of 150mgl of anthraquinone Remazol Brilliant Blue R dye in three subsequent decolorization cycles and the degradation capacity was not negatively affected by the presence of 10Saccharomyces cerevisiae cells per ml in the mixed culture. The yeast was not able to degrade the dye. I. lacteus biofilm was also resistant to bacterial infection with E. coli. Inoculation of the yeast to pre-formed I. lacteus biofilm culture resulted in a reduction of fungal biomass by 27%. Levels of LiP, MnP and laccase of I. lacteus were not much influenced by S. cerevisiae or E. coli. Similar resilience of P. ostreatus biofilms was observed after exposure to yeast Issatchenkia occidentalis when the fungal degradation capacity measured with Reactive Orange 16 azo dye was maintained over two decolorization cycles. I. occidentalis did not degrade the dye under the conditions used. Formation of densely packed fungal biofilms with abundant extracellular polysaccharide was not impeded by the yeast. Increase of MnP and laccase levels attributable to the presence of I. occidentalis was observed.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.scitotenv.2017.02.079DOI Listing
July 2017

Effect of bacteria on the degradation ability of Pleurotus ostreatus.

Sci Total Environ 2017 Apr 7;584-585:1114-1120. Epub 2017 Feb 7.

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

White-rot fungi are efficient degraders of lignin whose extracellular enzymes have a potential to degrade organopollutants. In natural conditions these fungi enter into interactions with other organisms, which may affect their biodegradation capacity. The aim was to investigate the ability of Pleurotus ostreatus to form stable biofilms and to test the capacity of the fungus to degrade Remazol Brilliant Blue R in mixed cultures with bacteria. Bacterial counts were determined to see the behavior of the bacterium in the mixed culture with the fungus. In axenic conditions, the homogenized fungal mycelium was able to form an active biofilm which quickly degraded the dye. The addition of Pseudomonas fluorescens or Bacillus licheniformis bacteria at 10CFU·mL did not affect the decolorization rate by 7-d-old fungal biofilms where the decolorization rate reached 90%. In contrast, when fragments of the fungal mycelium were used for inoculation to pre-formed biofilm of P. fluorescens, the biofilm was allowed to develop for one week's time, no decolorization of RBBR was observed and low activities of MnP and laccase were detected. The use of agar disks covered with fungal mycelium for the inoculation to pre-formed biofilm of P. fluorescens resulted in a fully developed biofilm that decolorized RBBR with similar efficiency as the pure P. ostreatus. The difference between the agar-disk- and homogenized-mycelium inoculated fungal biofilms was corroborated by the measurement of total fungal biofilm biomass that was 6-fold lower in the latter biofilm. Capability of the fungus to overcome the competition of the bacterial biofilm thus depended on the type of fungal growth centres, where intact hyphae were superior to the fragments of mycelium. A similar effect was not observed with the biofilms of B. licheniformis where the bacterial growth was less massive. The ability of P. ostreatus biofilms to resist massive bacterial stress was demonstrated.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.scitotenv.2017.01.171DOI Listing
April 2017

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.
View Article and Find Full Text PDF

Download full-text PDF

Source
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.
View Article and Find Full Text PDF

Download full-text PDF

Source
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.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.watres.2013.07.050DOI Listing
December 2013

The use of the fungus Dichomitus squalens for degradation in rotating biological contactor conditions.

Bioresour Technol 2012 Jun 2;114:241-6. Epub 2012 Apr 2.

Section of Ecology, Institute of Microbiology, Academy of Sciences of the Czech Republic, Prague, Czech Republic.

Biodegradation potential of Dichomitus squalens in biofilm cultures and rotating biological contactor (RBC) was investigated. The fungus formed thick biofilms on inert and lignocellulosic supports and exhibited stable activities of laccase and manganese peroxidase to reach 40-62 and 25-32% decolorization of anthraquinone Remazol Brilliant Blue R and heterocyclic phthalocyanine dyes, respectively. The decolorization ceased when glucose concentration dropped to 1 mmol l(-1). In RBC reactor, respective decolorizations of Remazol Brilliant Blue R and heterocyclic Methylene Blue and Azure B dyes (50 mg l(-1)) attained 99%, 93%, and 59% within 7, 40 and 200 h. The fungus exhibited tolerance to coliform and non-coliform bacteria on rich organic media, the inhibition occurred only on media containing tryptone and NaCl. The degradation efficiency in RBC reactor, capability to decolorize a wide range of dye structures and tolerance to bacterial stress make D. squalens an organism applicable to remediation of textile wastewaters.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.biortech.2012.03.080DOI Listing
June 2012

Reduction in the mutagenicity of synthetic dyes by successive treatment with activated sludge and the ligninolytic fungus, Irpex lacteus.

Environ Mol Mutagen 2006 Aug;47(7):533-40

University of Ostrava, Chittussiho 10, 70010 Slezská Ostrava, Czech Republic.

Synthetic dyes are released in wastewater from textile manufacturing plants, and many of these dyes are genotoxic. In the present study, the mutagenicity of azo, anthraquinone, and triphenyl methane dyes was investigated before and after successive biodegradation with activated sludge and the ligninolytic fungus, Irpex lacteus. Two biodegradation systems were used to reduce the genotoxicity of dyes that were not efficiently inactivated by activated sludge alone. Mutagenicity was monitored with the Salmonella reversion assay conducted with the base-pair substitution detector strains, TA100 and YG1042, and the frame-shift detector strains, TA98 and YG1041, with and without rat liver S9. All dyes except for Congo Red (CR) were mutagenic with S9 activation. Assays conducted with the dyes indicated that only the azo dye Reactive Orange 16 (RO16) was mutagenic in both TA98 and TA100. Methyl Red and Disperse Blue 3 (DB3) were mutagenic in TA98, YG1041 and YG1042, while Reactive Black 5 was mutagenic in YG1041 and YG1042. Remazol Brilliant Blue R (RBBR), Crystal violet (CV) and Bromophenol Blue (BPB) were mutagenic only in TA98, but the toxicity of the latter two dyes complicated the evaluation of their mutagenicity. CR was not mutagenic in any of the tester strains. Biodegradation studies conducted with RO16 and DB3 indicated that the two-step biodegradation process reduced the mutagenic potential of RO16 and DB3 to a greater extent than activated sludge alone; the mutagenicity of the two dyes was reduced by 95.2% and 77.8%, respectively, by the two-step process. These data indicate that the combined biodegradation process may be useful for reducing the mutagenicity associated with wastewater from textile factories that contain recalcitrant dyes.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1002/em.20224DOI Listing
August 2006

Comparative use of bacterial, algal and protozoan tests to study toxicity of azo- and anthraquinone dyes.

Chemosphere 2006 Jun 16;63(9):1436-42. Epub 2005 Nov 16.

Laboratory of Experimental Mycology, Institute of Microbiology, Academy of Sciences of the Czech Republic, Vídenská 1083, 142 20 Prague 4, Czech Republic.

Toxicity of two azo dyes (Reactive Orange 16 (RO16); Congo Red (CR)) and two anthraquinone dyes (Remazol Brilliant Blue R (RBBR); Disperse Blue 3 (DB3)) were compared using bacterium Vibrio fischeri, microalga Selenastrum capricornutum and ciliate Tetrahymena pyriformis. The following respective endpoints were involved: acute toxicity measured as bacterial luminescence inhibition, algal growth inhibition, and the effects on the protozoa including viability, growth inhibition, grazing effect and morphometric effects. In addition, mutagenicity of the dyes was determined using Ames test with bacterium Salmonella typhimurium His(-). DB3 dye was the most toxic of all dyes in the bacterial, algal and protozoan tests. In contrast to other dyes, DB3 exhibited mutagenic effects after metabolic activation in vitro in all S. typhimurium strains used. Of the methods applied, the algal test was the most sensitive to evaluate toxicity of the dyes tested.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.chemosphere.2005.10.002DOI Listing
June 2006