0000000000465271

AUTHOR

Karlis Svirksts

0000-0002-4144-8480

showing 7 related works from this author

Global effects of ade8 deletion on budding yeast metabolism

2021

AbstractPurine auxotrophy is a typical marker for many laboratory yeast strains. Supplementation of additional purine source (like adenine) is necessary to cultivate these strains. If not supplied in adequate amounts, purine starvation sets in. We tested purine starvation effects in budding yeast Saccharomyces cerevisiae ade8 knockout. We explored effects brought by purine starvation in cellular, central carbon metabolism and in the global transcriptome level.We observed that cells cultivated in purine depleted media became significantly more tolerant to severe thermal, oxidative and desiccation stresses when compared to the cells cultivated in media with all necessary supplements. When sta…

Purinechemistry.chemical_compoundbiologyChemistryAuxotrophySaccharomyces cerevisiaeAdenylate kinaseRNAbiology.organism_classificationPurine metabolismYeastIntracellularCell biology
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Effect of hydrogen peroxide on the dehydrogenase and quinone-reductase activity of irradiated Lactobacillus plantarum cells

2020

Abstract The resistance of lactobacilli to oxidative stress is of great importance for their applicability as probiotics. This study aimed to evaluate the response of Lactobacillus plantarum strain ATCC® 14917™, grown in either de Man, Rogosa, and Sharpe agar (MRS medium) or tryptic soy broth (TSB medium), to 1–2 mM H2O2 after the exposure to different doses of ionising radiation. Two bacterial extracellular enzyme groups, dehydrogenases (DHAs) and quinone reductases (QRs), served as the criteria of viability and antioxidant activity, respectively. The irradiated L. plantarum culture grown in TSB showed increased QR activity at irradiation doses of 2–50 Gy, with the maximum activity at 10 G…

0106 biological sciencesAntioxidantfood.ingredientmedicine.medical_treatmentDehydrogenase01 natural sciencesTryptic soy brothchemistry.chemical_compound0404 agricultural biotechnologyfoodQuinone Reductases010608 biotechnologymedicineAgarFood scienceHydrogen peroxidechemistry.chemical_classificationbiologyfood and beverages04 agricultural and veterinary sciencesbiology.organism_classification040401 food scienceEnzymechemistryLactobacillus plantarumFood ScienceLWT
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Drying enhances immunoactivity of spent brewer's yeast cell wall β-D-glucans.

2015

Due to immunological activity, microbial cell wall polysaccharides are defined as 'biological response modifiers' (BRM). Cell walls of spent brewer's yeast also have some BRM activity. However, up to date there is no consensus on the use of spent brewer's yeast D-glucan as specific BRM in humans or animals. The aim of this paper is to demonstrate the potential of spent brewer's yeast β-D-glucans as BRM, and drying as an efficient pretreatment to increase β-D-glucan's immunogenic activity. Our results revealed that drying does not change spent brewer's yeast biomass carbohydrate content as well as the chemical structure of purified β-D-glucan. However, drying increased purified β-D-glucan TN…

Carbohydrate contentbeta-GlucansChemical structureBioengineeringSaccharomyces cerevisiaeBiologyPolysaccharideApplied Microbiology and BiotechnologyCell wallchemistry.chemical_compoundCell WallSpectroscopy Fourier Transform InfraredAnimalsDesiccationCells Culturedchemistry.chemical_classificationMice Inbred ICRExtraction (chemistry)Fungal PolysaccharidesGeneral MedicineYeastPleurancarbohydrates (lipids)stomatognathic diseaseschemistryBiochemistryYeast biomassMacrophages PeritonealBiotechnologyJournal of biotechnology
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Spectroscopic and electrochemical study of interactions between DNA and different salts of 1,4-dihydropyridine AV-153

2020

1,4-dihydropyridines (1,4-DHP) possess important biochemical and pharmacological properties, including antimutagenic and DNA-binding activity. The latter activity was first described for water-soluble 1,4-DHP with carboxylic group in position 4, the sodium salt of the 1,4-DHP derivative AV-153 among others. Some data show the modification of physicochemical properties and biological activities of organic compounds by metal ions that form the salts. We demonstrated the different affinity to DNA and DNA-protecting capacity of AV-153 salts, depending on the salt-forming ion (Na, K, Li, Rb, Ca, Mg). This study aimed to use different approaches to collate data on the DNA-binding mode of AV-153-N…

Circular dichroismGuanine030303 biophysicsIntercalation (chemistry)Biophysicslcsh:MedicineCircular dichroismG-quadruplexBiochemistryMedicinal chemistryGeneral Biochemistry Genetics and Molecular BiologyNucleobase03 medical and health scienceschemistry.chemical_compoundCircular voltammetryMoleculeDenaturation (biochemistry)DNA bindingMolecular Biology14-dihydropyridines030304 developmental biologyAV-153 salts0303 health sciencesGeneral Neurosciencelcsh:RGeneral MedicineG-quadruplexeschemistryFourier-transformed infrared spectroscopySpectrofluorimetryGeneral Agricultural and Biological SciencesDNAPeerJ
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Spectrophotometric study of DNA interactions with ftorafur and its elementoorganic derivatives

2017

ABSTRACTFtorafur is an antimetabolite antitumour drug successfully used for treatment of various tumours. It is generally accepted that ftorafur is converted to 5-fluoruracil. However, some data indicate direct interactions of the compound with DNA. To test this hypothesis we have performed spectrophotometric study of DNA interactions of ftorafur and some of its elementoorganic derivatives with DNA. UV-VIS spectra of the tested compounds were recorded in absence and presence of increasing amounts of DNA. DNA caused a hypochromic effect in spectra of ftorafur, similar, but weaker effect was observed in 5-fluoruracil spectra. Trimethylgermyl derivative of ftorafur manifested a higher DNA-bind…

0301 basic medicine030102 biochemistry & molecular biologyChemistryStereochemistryHealth Toxicology and MutagenesisDna interactionIntercalation (chemistry)Infrared spectroscopyAntitumour drug010402 general chemistry01 natural sciencesPollution0104 chemical sciences03 medical and health scienceschemistry.chemical_compoundUltraviolet visible spectroscopyBromideEnvironmental ChemistryDNADNA-ethidiumNuclear chemistryToxicological & Environmental Chemistry
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Modeling the mobility of glyphosate from two contrasting agricultural soils in laboratory column experiments

2019

Glyphosate (GLP) currently is one of the most widely used herbicides worldwide. The persistence of GLP and its major metabolite, aminomethylphosphonic acid (AMPA) in the environment has been described by other authors. This study was aimed at comparing the GLP and AMPA behavior in sandy and loamy sand soils after spiking with enhanced (445 µg g−1) concentrations of GLP in herbicide KLINIK® (Nufarm, Austria) and bioaugmentation followed by 40 days weathering and a consistent three-stage leaching in a laboratory column experiment. Soil samples were obtained from mineral topsoil (0–10 cm) within former agricultural lands where soil parent material was formed by glacigenic deposits. The total a…

MetaboliteGlycineTetrazoles010501 environmental sciences01 natural sciencesPersistence (computer science)chemistry.chemical_compoundSoilOrganophosphorus CompoundsSpectroscopy Fourier Transform InfraredToxicity TestsAnimalsSoil PollutantsAminomethylphosphonic acid0105 earth and related environmental sciencesHerbicidesAgriculture04 agricultural and veterinary sciencesGeneral MedicineIsoxazolesPollutionchemistryDaphniaEnvironmental chemistryGlyphosateSoil water040103 agronomy & agriculture0401 agriculture forestry and fisheriesColumn (botany)Food Science
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Optimization of Nitrification Process by a Bacterial Consortium in the Submerged Biofiltration System with Ceramic Bead Carrier

2014

Laboratory-scale solid phase submerged system was developed to study the process of ammonium biodegradation. Ceramic beads were found to be an appropriate carrier material for the attachment of thePNN bacterial consortium (Pseudomonas sp., Nitrosomonas sp., Nitrobacter sp.) exhibiting nitrification/denitrification activity. This consortium was previously isolated from a biological activated sludge process at a fish factory wastewater treatment plant. Three organic amendments - molasses, humic acid extract, and malt extract - were used for the ceramic bead pretreatment. Molasses significantly enhanced (p<0.05) the process of bacteria attachment onto the ceramic carrier and further ammonium r…

DenitrificationBiodegradationPulp and paper industryApplied Microbiology and BiotechnologyBiochemistryMicrobiologyMicrobiologychemistry.chemical_compoundActivated sludgechemistryWastewaterBiofilterAmmoniumSewage treatmentNitrificationBiotechnologyJournal of Microbial &amp; Biochemical Technology
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