Publications by authors named "Irena Kolouchova"

This research paper presents a novel approach to the green synthesis of silver nanoparticles (AgNPs) using viticultural waste, allowing to obtain NP dispersions with distinct properties and morphologies (monodisperse and polydisperse AgNPs, referred to as mAgNPs and pAgNPs) and to compare their biological activities. Our synthesis method utilized the ethanolic extract of Vitis vinifera pruning residues, resulting in the production of mAgNPs and pAgNPs with average sizes of 12 ± 5 nm and 19 ± 14 nm, respectively. Both these AgNPs preparations demonstrated an exceptional stability in terms of size distribution, which was maintained for one year.

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Radon springs, characterized by their high concentrations of radon gas (Rn222), are extreme environments with unique physicochemical conditions distinct from conventional aquatic ecosystems. Our research aimed to investigate microbial life in radon springs, focusing on isolating extremophilic bacteria and assessing their resistance to adverse conditions. Our study revealed the prevalence of Actinomycetia species in the radon spring environment.

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Article Synopsis
  • This paper investigates various fungal endophytes found in Vitis vinifera (grapevine) leaves and canes in the Czech Republic, using morphological and genetic analyses.
  • A total of 16 different fungal species were identified, including some common ones and several lesser-known fungi, highlighting the diversity of fungal life associated with this plant.
  • The research is pioneering in the context of Central Europe, providing new insights into the taxonomy, ecology, and geographical distribution of V. vinifera's fungal endophytes.
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Microscopic filamentous fungi are ubiquitous microorganisms that adapt very easily to a variety of environmental conditions. Due to this adaptability, they can colonize a number of various surfaces where they are able to start forming biofilms. Life in the form of biofilms provides them with many benefits (increased resistance to desiccation, UV radiation, antimicrobial compounds, and host immune response).

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Boswellic acids are biologically active pentacyclic terpenoid compounds derived from sp. plants. Extracts containing these acids have a number of positive effects on human health, especially in the treatment of inflammation, arthritis, or asthma.

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Fungal endophytes occurring in grapevine ( L.) are usually important sources of various compounds with biological activities with great potential for use in agriculture. Nevertheless, many species isolated from this plant belong to the genera , , or all of which are well-known to produce mycotoxins.

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The ever-growing range of possible applications of nanoparticles requires their mass production. However, there are problems resulting from the prevalent methods of nanoparticle production; physico-chemical routes of nanoparticle synthesis are not very environmentally friendly nor cost-effective. Due to this, the scientific community started exploring new methods of nanoparticle assembly with the aid of biological agents.

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The use of antibiotics or antifungals to control infections caused by pathogenic microorganisms is currently insufficiently effective because of their emerging resistance. Thanks to the ability of microorganisms to form a biofilm and thus increase their resistance to administered drugs even more, modern medicine faces the task of finding novel substances to combat infections caused by them. In this regard, the effects of essential oils or plant extracts are often studied.

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There is a growing interest in the potential and application of metal nanoparticles across many fields. A vast array of techniques for metal nanoparticle synthesis has been discovered; however, sustainability, cost-effectiveness, and environmental concerns favor the green biological approach, using various plant and microbial sources. This review describes the diversity in green methods for nanoparticle biosynthesis, antimicrobial properties of metal nanoparticles and their potential applications.

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canes are waste material of grapevine pruning and thus represent cheap source of high-value polyphenols. In view of the fact that resistance of many pathogenic microorganisms to antibiotics is a growing problem, the antimicrobial activity of plant polyphenols is studied as one of the possible approaches. We have investigated the total phenolic content, composition, antioxidant activity, and antifungal activity against biofilm of an extract from winter canes and a commercially available extract from blue grapes.

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Microbial biofilms formed by pathogenic and antibiotic-resistant microorganisms represent a serious threat for public health in medicine and many industrial branches. Biofilms are involved in many persistent and chronic infections, the biofouling of water and food contamination. Therefore, current research is involved in the development of new treatment strategies.

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: Hopanoids modify plasma membrane properties in bacteria and are often compared to sterols that modulate membrane fluidity in eukaryotes. In some microorganisms, they can also allow adaptations to extreme environments. : Hopanoids were identified by liquid chromatography-mass spectrometry in fourteen strains of thermophilic bacteria belonging to five genera, i.

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Sixteen strains of five genera of thermophilic bacteria, i.e., , and were cultivated at a temperature from 42 to 70 °C.

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The analysis of triacylglycerols and phospholipids - phosphatidylcholines allowed the use of shotgun lipidomics to identify very long-chain fatty acids and very long-chain polyunsaturated fatty acids in microalgae. These fatty acids were determined in triacylglycerols by positive electrospray ionization of neutral loss scans of different fatty acids, e.g.

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Four bacterial isolates, which produced polyunsaturated fatty acids (PUFA), were isolated from water samples of radioactive springs collected from Jáchymov spa. Jáchymov (Sankt Joachimsthal) is a city in northwestern Bohemia, where Marie and Pierre Curie isolated radium in 1898 from the mineral uraninite. To date, four springs (Agricola, Behounek, C1, and Curie) have been used for spa purposes, that is for the treatment of nervous and rheumatic disorders by constantly produced radioactive gas radon ( Rn) dissolved in the water.

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Mass spectrometry-based shotgun lipidomics was applied to the analysis of sphingolipids of 11 yeast strains belonging to four genera, that is Cryptococcus, Saccharomyces, Schizosaccharomyces, and Wickerhamomyces. The analysis yielded comprehensive results on both qualitative and quantitative representation of complex sphingolipids of three classes-phosphoinositol ceramide (PtdInsCer), mannosyl inositol phosphoceramide (MInsPCer), and mannosyl diinositol phosphoceramide (M(InsP) Cer). In total, nearly 150 molecular species of complex sphingolipids were identified.

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Microorganisms that cause chronic infections exist predominantly as surface-attached stable communities known as biofilms. Microbial cells in biofilms are highly resistant to conventional antibiotics and other forms of antimicrobial treatment; therefore, modern medicine tries to develop new drugs that exhibit anti-biofilm activity. We investigated the influence of a plant polyphenolic compound resveratrol (representative of the stilbene family) on the opportunistic pathogen Trichosporon cutaneum.

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Enantiomers of triacylglycerols (TAGs) containing any combination of very long chain fatty acids (VLCFAs) and/or very long chain polyunsaturated fatty acids (VLCPUFAs) with diolein, dilinolein and didocosahexaenoin were synthesized. Gradient non-aqueous reversed-phase high-performance liquid chromatography/high resolution atmospheric pressure chemical ionization-tandem mass spectrometry (NARP-HPLC/HRMS-APCI) and chiral liquid chromatography were used for the separation and identification of molecular species of these TAGs. Further, NARP-LC and chiral LC were used to separate natural mixtures of TAGs obtained from four natural sources, i.

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Lipids are among the most important organic compounds found in all living cells, from primitive archaebacteria to flowering plants or mammalian cells. They form part of cell walls and constitute cell storage material. Their biosynthesis and metabolism play key roles in faraway topics such as biofuel production (third-generation biofuels produced by microorganisms, e.

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We investigated the possibility of utilizing unusual carbon sources by three yeast strains: DBM 2136, CCY 30-5-10, and CCY 30-26-36. These strains are characterized by high biomass yield, ability to accumulate high amounts of lipids, and their potential as producers of dietetically important fatty acids. The aim of this work was the production of nutritionally important fatty acids by utilization of n-alkanes with an odd number of carbon atoms, alone and in combination with glucose and subsequent analysis of microbial lipids accumulation and fatty acid profile.

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Mid-exponential cultures of two traditional biotechnological yeast species, winery Saccharomyces cerevisiae and the less ethanol tolerant bottom-fermenting brewery Saccharomyces pastorianus, were exposed to different concentrations of added ethanol (3, 5 and 8%) The degree of ethanol-induced cell stress was assessed by measuring the cellular activity of superoxide dismutase (SOD), level of lipid peroxidation products, changes in cell lipid content and fatty acid profile. The resveratrol as an antioxidant was found to decrease the ethanol-induced rise of SOD activity and suppress the ethanol-induced decrease in cell lipids. A lower resveratrol concentration (0.

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Microbial adhesion to surfaces and the subsequent biofilm formation may result in contamination in food industry and in healthcare-associated infections and may significantly affect postoperative care. Some plants produce substances with antioxidant and antimicrobial properties that are able to inhibit the growth of food-borne pathogens. The aim of our study was to evaluate antimicrobial and anti-biofilm effect of baicalein, resveratrol, and pterostilbene on Candida albicans, Staphylococcus epidermidis, Pseudomonas aeruginosa, and Escherichia coli.

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Yeast lipids and fatty acids (FA) were analyzed in Saccharomyces pastorianus from seven breweries and in the dietary yeast supplement Pangamin. GC-MS identified more than 30 FA, half of which were very-long chain fatty acids (VLCFA) with hydrocarbon chain lengths of ≥22 C atoms. Positional isomers ω-9 and ω-7 were identified in FA with C18-C28 even-numbered alkyl chains.

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Analysis of polar lipids from eight psychrophilic yeasts (Cryptococcus victoriae, Cystofilobasidium capitatum, Holtermaniella wattica, Mrakiella aquatica, M. cryoconiti, Rhodotorula lignophila, Kondoa malvinella and Trichosporon aggtelekiense) grown at 4-28°C by hydrophilic interaction liquid chromatography/high resolution electrospray ionization tandem mass spectrometry determined 17 classes of lipids and identified dozens of molecular species of phospholipids including their regioisomers. Most of the yeasts were able to grow over the whole temperature range, reaching the highest biomass at 4 or 10°C.

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The growth of microorganisms is affected by cultivation conditions, concentration of carbon and nitrogen sources and the presence of trace elements. One of the new possibilities of influencing the production of cell mass or lipids is the use of lanthanides. Lanthanides are biologically non-essential elements with wide applications in technology and industry and their concentration as environmental contaminants is therefore increasing.

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