Publications by authors named "Dorota Grabek-Lejko"

The aim of the present study was to compare the antioxidant, antibacterial and antiviral activities of Podkarpackie coniferous honeydew honey and Manuka honey. The quality of tested honey samples (honeydew-12 and Manuka-4) regarding honey standard was evaluated as well as additional indicators (methylglyoxal, total phenolics and HPTLC phenolic profile, antioxidant potential, glucose oxidase activity, and hydrogen peroxide) were compared. Antibacterial potential was analyzed against Gram-positive (S.

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The purpose of this study was to isolate, identify, and evaluate the antibacterial and probiotic potential of bacteria from honeydew honey collected in Poland. Isolates (189 colonies from 10 honey samples) were evaluated for their antimicrobial activity against , , and , and then identified by MALDI-TOF-MS. The isolates with the greatest antimicrobial properties were screened for their probiotic potential.

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The aim of this study was to compare the biological properties, such as antiviral, antibacterial, and antioxidant, of recently described pentaploid species with tetraploid taxa growing in similar habitats including , , and . The antiviral potential was analyzed against bacteriophages with different genetic material: phi6 (a surrogate for the SARS-CoV-2 virus), T7, phiX174, and MS2. Antibacterial properties of fruit and leaf extracts were determined against , , , and .

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is considered the main pathogen responsible for dental caries, one of the major infectious diseases, affecting more than 4 billion people worldwide. Honey is a natural product with well-known antibacterial potential against several human pathogens. The aim of the study was to evaluate the antibacterial efficacy of Polish honey against and analyze the role of some bioactive substances on its antibacterial action.

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Background: Birch is a tree with a common occurrence in the environment and its organs are used in the form of herbal material. An important aspect of this study is birch pollen, which is a problem for allergy sufferers, and due to a variety of environmental conditions, its allergenicity may increase. Among the organs studied, inflorescences deserve attention, which, as seen from an overview of the literature, are analysed for the content of heavy metals for the first time in this study.

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The aim of this study was to investigate the effect of blackberry and raspberry fruits (1 and 4%) and leaves (0.5 and 1%) on the biological activities of rape honey. Honey and plant material extracts were analyzed regarding total phenolic, flavonoid, anthocyanin contents, HPTLC and HPLC polyphenol profiles, as well as antioxidant activity.

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L., walnut, is a large, long-living tree, cultivated in temperate climates around the world. It is highly appreciated for its nutritional kernels and high-quality timber.

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The effect of adding the chokeberry fruit additive to rape honey was studied with regard to the physicochemical properties and biological activity. Two samples of dried powdered fruits were used to enrich the honey (1 and 4% v/v) during creaming. The obtained products were characterized in terms of sugar content, acidity, conductivity, total phenolic, flavonoid and anthocyanin contents and HPTLC polyphenol profiles.

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Honey variety is commonly defined by beekeepers based on nectar flow availability and the only laboratory method to provide verification is the melissopalynological analysis. Therefore, a quick and simple method for accurate assessment of honey variety is still being researched. The aim of the study was to evaluate the antioxidant activity of honey as an indicator of variety through the use of multivariate statistical analysis.

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Lignocellulosic biomass belongs to main sustainable renewable sources for global energy supply. One of the main challenges in the conversion of saccharified lignocellulosic biomass into bioethanol is the utilization of xylose, since lignocellulosic feedstocks contain a significant amount of this pentose. The non-conventional thermotolerant yeast Ogataea polymorpha naturally ferments xylose to ethanol at elevated temperatures (45°C).

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Seventeen natural sweeteners available on the Polish market were screened for total phenolic content, by the Folin-Ciocalteu method, and for antioxidant activity, using the ferric reducing antioxidant power (FRAP) assay and the 2,2'-Azinobis (3-ethylbenzthiazoline-6-sulphonic acid) radical cation decolorization assay (ABTS(·+)). In addition, we analyzed antibacterial activities against Staphylococcus aureus strains: both those susceptible and those resistant to methicillin (MRSA). The results of the study showed that total phenolic content, antioxidant activity and antibacterial activity differ widely among different samples of sweeteners.

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Methylotrophic yeasts are unique eukaryotic organisms, that can metabolize toxic one-carbon substrate, methyl alcohol or methanol. About 50 species of methylotrophic yeasts is known, among them 4 species are the best studied: Pichia methanolica, Hansenula polymorpha, Pichia pastoris i Candida boidinii. These organisms, especially P.

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The ability of baker's yeast Saccharomyces cerevisiae and of the thermotolerant methylotrophic yeast Hansenula polymorpha to produce ethanol during alcoholic fermentation of glucose was compared between wild-type strains and recombinant strains possessing an elevated level of intracellular glutathione (GSH) due to overexpression of the first gene of GSH biosynthesis, gamma-glutamylcysteine synthetase, or of the central regulatory gene of sulfur metabolism, MET4. The analyzed strains of H. polymorpha with an elevated pool of intracellular GSH were found to accumulate almost twice as much ethanol as the wild-type strain during glucose fermentation, in contrast to GSH1-overexpressing S.

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A new method for the selection of Pichia stipitis and Hansenula polymorpha yeast mutants with altered capability to ferment xylose to ethanol was developed. The method is based on the ability of P. stipitis and H.

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