Taste and odor (T&O) issues are pervasive challenges in water supply systems, significantly compromising water quality and safety. Actinobacteria are a major source of T&O issues in drinking water reservoirs, particularly during periods devoid of algal blooms. However, conventional culture media fail to cultivate actinobacteria efficiently, limiting our ability to assess their role in T&O events accurately. In this study, we first evaluated several traditional media for their capacity to cultivate actinobacteria and then developed a novel actinobacterial enrichment culture medium (AECM) designed to improve cultivation efficiency. The results indicated that although the Gause No. 1 medium achieved higher cultivation efficiency, it only recovered approximately one-quarter of the actinobacterial genera present in water samples. In contrast, AECM, formulated based on the metabolic activity of actinobacteria, demonstrated a 30 % improvement in cultivation efficiency compared to conventional media and successfully isolated two odor-producing non-Streptomyces genera. This approach provides a new method for identifying microbial sources of T&O in drinking water systems and offers valuable insights into the odor-producing mechanisms of actinobacteria, ultimately enhancing the safety and palatability of drinking water.

• Klíčová slova
• Actinobacteria, Carbon source metabolic activity, Culture medium, Drinking water, Taste & odor,
• MeSH
• Actinobacteria * růst a vývoj   izolace a purifikace   metabolismus   MeSH
• chuť * MeSH
• kultivační média MeSH
• mikrobiologie vody MeSH
• odoranty * analýza   MeSH
• pitná voda * mikrobiologie   MeSH
• zásobování vodou MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• kultivační média MeSH
• pitná voda * MeSH

This study aimed to determine the paraoxonase activity and prooxidant-antioxidant balance in the brain tissue of Wistar rats following subacute treatment with selected K-oximes. Each K-oxime was administered intramuscularly (0.1 LD50/kg) twice per week for four weeks, and 7 days after the last treatment, the paraoxonase activity (PON1), the prooxidant-antioxidant balance (PAB), the levels of superoxide anion radical (O2•-), the concentration of nitrite (NO2-) and the content of free protein thiol groups in the brain homogenates were evaluated. The PON1 and PAB activity were significantly reduced in almost all oxime-treated groups (p < 0.01 and p < 0.001, respectively). The concentrations of O2•- were significantly increased in the obidoxime-, K048-, K074- and K075-treated groups (p < 0.001), while the levels of NO2- was significantly decreased in asoxime-, obidoxime-, K074 and K075-treated rats (p < 0.01, p < 0.001, respectively). The content of Thiol groups was significantly elevated in all oxime-treated groups (p < 0.001). Continuing our previously published data, these results confirmed that applied K-oximes improved the oxidative status and further harmful systemic effects of rats after subacute administration.

• Klíčová slova
• Brain tissue, Oximes, Paraoxonase activity, Rats, Subacute toxicity,
• MeSH
• antioxidancia * metabolismus   MeSH
• aryldialkylfosfatasa * metabolismus   MeSH
• dusitany metabolismus   MeSH
• krysa rodu Rattus MeSH
• mozek * účinky léků   metabolismus   enzymologie   MeSH
• oximy * farmakologie   aplikace a dávkování   MeSH
• potkani Wistar MeSH
• sulfhydrylové sloučeniny metabolismus   MeSH
• superoxidy metabolismus   MeSH
• zvířata MeSH
• Check Tag
• krysa rodu Rattus MeSH
• mužské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• antioxidancia * MeSH
• aryldialkylfosfatasa * MeSH
• dusitany MeSH
• oximy * MeSH
• sulfhydrylové sloučeniny MeSH
• superoxidy MeSH

Encapsulation of Plant Growth-Promoting Rhizobacteria (PGPR) in hydrogel carriers is a cutting-edge approach in developing agricultural bioinoculants, aiming to improve soil fertility and crop yield. Hydrogels provide protection against environmental stress, though traditional methods using external gel-forming agents limit economic viability. This study presents a novel approach, demonstrating the entrapment of Azotobacter vinelandii, a promising PGPR, within a gel matrix formed by Ca2+-induced crosslinking of its own exopolysaccharide, alginate. Among the five strains evaluated, A. vinelandii DSM 87, DSM 720, and DSM 13529 showed the highest alginate production, peaking at 4.9 ± 0.6 g/L, 3.5 ± 0.5 g/L, 3.8 ± 0.8 g/L, and enabling stable gel formation by the fourth day of cultivation. These strains also exhibited molecular weights and chemical structures of alginate suitable for effective gelation upon Ca2+addition. Additionally, these strains demonstrated significant plant growth-promoting activities, including indole acetic acid production (up to 10.5 μg/mL), siderophore release, and phosphate solubilization, further validating their potential for sustainable bioinoculant production. Finally, the viability of the A.vinelandii cells released from the gels was experimentally verified. Our findings support a feasible, cost-effective method for bioinoculant production that leverages A. vinelandii's intrinsic capabilities, offering a sustainable alternative to conventional agricultural practices.

• Klíčová slova
• Alginate, Azotobacter vinelandii, Bioinoculants, Hydrogels, Polyhydroxyalkanoates,
• MeSH
• algináty * chemie   MeSH
• Azotobacter vinelandii * metabolismus   chemie   MeSH
• bakteriální polysacharidy * chemie   MeSH
• fosfáty metabolismus   MeSH
• hydrogely * chemie   MeSH
• kyseliny indoloctové metabolismus   MeSH
• vápník chemie   MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• algináty * MeSH
• bakteriální polysacharidy * MeSH
• fosfáty MeSH
• hydrogely * MeSH
• indoleacetic acid MeSH Prohlížeč
• kyseliny indoloctové MeSH
• vápník MeSH

Sustainable land management in Mediterranean vineyards faces several challenges, including land degradation, drought, and climate change impacts, often exacerbated by extreme weather events. We hypothesised that biochar enhances the soil sponge function, i.e. a combination of infiltration and retention of rainwater, thus promoting vegetation growth, and that this can be considered an indirect mechanism to reduce runoff and soil erosion. To address these hypotheses, we conducted a random-block design box lysimeter experiment from September 2019 to October 2020 under natural rainfall conditions at a slope gradient of 14.4. A Regosol soil type with sandy loam texture collected from the Bairrada's Denomination of Origin region (Central Portugal) was used. Soil treatments consisted of untreated soil as the control and woody biochar-amended soil with the maximum sustainable concentration of 4 % (w/w), both sown with a biodiverse pasture seed mixture. Biochar reduced runoff and soil erosion (fine earth fragment) by 50 % and 58 %. There was an improvement in soil physical and hydrological properties, i.e. bulk density decreased by 13.1 %, enhancing soil sponge function involving increasing water infiltration and soil water content by 50 % and 59 %. Soil water repellency only in the biochar-amended treatment remained within wettable conditions. The vegetation cover and aboveground biomass increased by 263 % and 198 %, respectively, due to an increase in soil pH to neutral conditions, improvement of essential nutrients (NPK) and the reduction of toxicity in biochar amendments. This study offers a practical strategy for sustainable soil management against traditional approaches, especially the observed biochar-vegetation synergy during hydrological seasonality (dry to wet conditions) in Mediterranean vineyards.

• Klíčová slova
• Atmospheric river (AR), Biochar, Nutrient cycling, Soil erosion, Soil hydrophobicity, Soil sponge function,
• MeSH
• dřevěné a živočišné uhlí * MeSH
• eroze půdy * MeSH
• farmy MeSH
• půda * chemie   MeSH
• voda MeSH
• zemědělství MeSH
• Publikační typ
• časopisecké články MeSH
• Geografické názvy
• Portugalsko MeSH
• Názvy látek
• biochar MeSH Prohlížeč
• dřevěné a živočišné uhlí * MeSH
• půda * MeSH
• voda MeSH

This study investigates the electrocoagulation/permanganate (EC/PM) process as a pre-treatment, followed by UV-activated peroxymonosulfate (PMS) and electro-peroxone (EP) treatments. This sequence is designed to effectively mineralize organic matter. Notably, PM was integrated into the EC process for the first time to enhance removal efficiency. The iron sludge generated from the EC/PM process (sludge-derived electrocoagulation; SDEC) was repurposed as a cost-effective source of iron oxide in the PMS/SDEC/UV treatment. Treatment optimization was achieved by adjusting the main operating parameters. A comprehensive analysis was conducted to assess the biodegradability and toxicity of the leachate post-treatment, including measurements of COD, BOD, TOC, ammonia levels, average oxidation state, biodegradability, organic carbon content, and spectroscopic methods. The results demonstrated substantial removal efficiencies across the treatment stages, with 98.9 % for COD, 94.9 % for BOD, 96.4 % for TOC, and 97.7 % for ammonia. Spectroscopic changes indicated that the leachate was broken down into smaller, more oxidized, and highly acidic molecules with an increased aliphatic structure while effectively eliminating aromatic compounds. The BOD5/COD ratio improved to 0.55, indicating that the treated leachate is suitable for biological treatment processes with significantly reduced toxicity. Overall, the sequence of treatment processes yielded promising results.

• Klíčová slova
• Electro-peroxone, Electrocoagulation, Landfill leachate, Permanganate, Peroxymonosulfate, Sequential treatment,
• MeSH
• chemické látky znečišťující vodu * chemie   MeSH
• odpad tekutý - odstraňování metody   MeSH
• peroxidy * chemie   MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• chemické látky znečišťující vodu * MeSH
• peroxidy * MeSH
• peroxymonosulfate MeSH Prohlížeč

A copper(II) tetrapyrazole-based complex of the composition of [Cu(tpyr)(H2O)(ONO2)]NO3 (1), where tpyr represents a tetradentate N-donor ligand formed by the condensation of 1H-pyrazole-5-carbaldehyde in NaOH/MeOH medium, has been prepared and characterized by elemental analysis, infrared spectroscopy, ultraviolet-visible spectroscopy, mass spectrometry, electron paramagnetic resonance and single-crystal X-ray diffraction. Spectrophotometric measurements demonstrated a remarkable peroxidase activity of the complex, which utilized hydrogen peroxide for the oxidation of phenolic compounds such as guaiacol or 3,5-dichloro-2-hydroxybenzene sulfonic acid. The optimum conditions for this reaction were found at pH 8 in ammonium bicarbonate buffer, although the activity was low but still detectable at pH 5-6 in ammonium acetate. As a peroxidase mimic, the complex exhibited enzyme-like Michaelis-Menten kinetics, showing a hyperbolic dependence of the reaction rate on hydrogen peroxide concentration. The determined Km and kcat values were 651 μmol·l-1 and 6.7 × 10-4 s-1, respectively, compared to 41 μmol·l-1 and 73 s-1 for horseradish peroxidase. EPR spectroscopy of the reaction mixture revealed no change in the copper (II) oxidation state during catalysis, suggesting that the oxidation of guaiacol may occur simultaneously with the reduction of hydrogen peroxide to water at the copper centre.

• Klíčová slova
• Copper(II), Crystal structure, MALDI-TOF, Peroxidase activity, Tetrapyrazole, XPS,
• MeSH
• biomimetické materiály * chemie   MeSH
• kinetika MeSH
• komplexní sloučeniny * chemie   chemická syntéza   MeSH
• krystalografie rentgenová MeSH
• měď * chemie   MeSH
• oxidace-redukce MeSH
• peroxid vodíku chemie   MeSH
• peroxidasa * chemie   MeSH
• pyrazoly * chemie   MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• komplexní sloučeniny * MeSH
• měď * MeSH
• peroxid vodíku MeSH
• peroxidasa * MeSH
• pyrazoly * MeSH

Plants rely on water and light for photosynthesis, but water droplets on leaves can focus light into high-intensity spots, risking photodamage. Excessive light can impair growth or induce cell death, making it essential for plants to detect and respond to light fluctuations. While Ca2+ signaling has been linked to high light (HL) acclimation, the subcellular dynamics remain unclear. Here, we investigate Ca2+ responses to HL exposure in Arabidopsis thaliana. Using a glass bead to simulate light-focusing by water droplets, a biphasic increase of Ca2+ concentration was detected in the chloroplast stroma by the genetically encoded calcium indicator YC3.6 and confirmed using a newly established stroma-localized R-GECO1 (NTRC-R-GECO1). The stromal response was largely independent of light wavelength and unaffected in phot1 phot2 and cry1 cry2 mutants. Chemical inhibition of photosynthetic electron transport, microscopy-based Fv/Fm experiments, and measurement of the reactive oxygen species (ROS)-redox balance with roGFP-based reporters and Singlet Oxygen Sensor Green (SOSG) chemical dye suggested that photodamage and singlet oxygen contribute to the stromal Ca2+ response. While blue and white light also triggered a Ca2+ response in the cytosol and nucleus, pharmacological inhibition with cyclopiazonic acid (CPA) and loss-of-function mutants of the Ca2+ transporters BIVALENT CATION TRANSPORTER 2 (BICAT2) and endoplasmic reticulum (ER)-type Ca2+-ATPase (ECA) suggested that the HL response depends on a Ca2+ exchange between the ER and chloroplast stroma. The response was primarily light dependent but accelerated by increasing external temperature. This study implicates a novel Ca2+-mediated acclimation mechanism to HL stress, a process of growing relevance in the context of climate change.

• Klíčová slova
• BICAT2, ECA, calcium signaling, chloroplast, endoplasmic reticulum, high light stress, photoinhibition, reactive oxygen species, temperature-dependent, water droplet,
• MeSH
• Arabidopsis * fyziologie   účinky záření   metabolismus   MeSH
• chloroplasty * metabolismus   účinky záření   MeSH
• fotosyntéza MeSH
• proteiny huseníčku metabolismus   genetika   MeSH
• reaktivní formy kyslíku metabolismus   MeSH
• světlo * MeSH
• vápník * metabolismus   MeSH
• vápníková signalizace * MeSH
• voda * metabolismus   MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• proteiny huseníčku MeSH
• reaktivní formy kyslíku MeSH
• vápník * MeSH
• voda * MeSH

Many agrochemicals disrupt redox homeostasis, yet the dynamics of oxidative stress responses in honey bees (Apis mellifera) remain insufficiently understood. This study established a controlled model to monitor ROS-related markers over time following paraquat injection, using Bayesian modeling to characterize time-dependent changes. We observed a transient rise in hydroperoxides and early fluctuation in adipokinetic hormone (AKH) levels, which declined and stabilized within 8 hours. No significant differences were detected in secondary lipid peroxidation products (TBARS) among treatments. While injection does not represent natural exposure pathways, it enables precise dosing and timing, avoiding variability from oral intake. This experimental design provides a tractable system to investigate oxidative stress mechanisms under defined conditions. Our findings underscore the importance of time-resolved analysis in redox physiology and offer a mechanistic framework to complement field-relevant toxicological studies in bees and other beneficial insects.

• Klíčová slova
• Bayesian modeling, Lipid peroxidation, Paraquat, Reactive oxygen species,
• MeSH
• Bayesova věta MeSH
• biologické markery metabolismus   MeSH
• herbicidy * toxicita   MeSH
• hmyzí hormony metabolismus   MeSH
• kyselina pyrrolidonkarboxylová analogy a deriváty   metabolismus   MeSH
• látky reagující s kyselinou thiobarbiturovou metabolismus   MeSH
• oligopeptidy metabolismus   MeSH
• oxidační stres * účinky léků   MeSH
• paraquat * toxicita   MeSH
• peroxid vodíku metabolismus   MeSH
• peroxidace lipidů účinky léků   MeSH
• včely metabolismus   účinky léků   MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• adipokinetic hormone MeSH Prohlížeč
• biologické markery MeSH
• herbicidy * MeSH
• hmyzí hormony MeSH
• kyselina pyrrolidonkarboxylová MeSH
• látky reagující s kyselinou thiobarbiturovou MeSH
• oligopeptidy MeSH
• paraquat * MeSH
• peroxid vodíku MeSH

Cryopreservation of dormant buds offers a reliable and cost-effective method for the long-term preservation of plant genetic resources, particularly for woody plants like raspberry (Rubus idaeus L.). This study aimed to develop an optimized protocol for the cryopreservation of dormant raspberry buds by investigating the role of dehydration and freezing conditions in maintaining bud viability. Dormant canes of two raspberry varieties, 'Sanibelle' and 'Willamette', were collected and prepared by dehydrating single-node cane segments at -4 °C until the desired water content was achieved. The study focused on assessing the impact of dehydration on bud viability and the physical state of water within the buds, using differential scanning calorimetry to analyse thermal transitions during cooling and heating. The cryopreservation process followed a two-step freezing protocol, with the first step involving slow cooling to -30 °C, followed by rapid immersion in liquid nitrogen (-196 °C). After cryopreservation, buds were thawed either slowly at +4 °C or rapidly at +38 °C, with rehydration taking place over 14 days. The study found that the most effective preservation (74-86 % of buds) occurred when the buds were dehydrated to 22-23 % humidity and had a water activity of 0.83-0.85. Rapid thawing significantly improved bud survival, especially for moderately dehydrated buds (with water content 25-35 %), while recrystallization during slow thawing was associated with lower viability. The results highlight the complexity of cryopreservation protocols, where factors such as dehydration levels, cooling and thawing rates, and bud dormancy status play crucial roles in ensuring successful long-term storage.

• Klíčová slova
• Cryopreservation, Crystallised water, Dehydration, Raspberry dormant buds, Two-step freezing, Water activity,
• MeSH
• diferenciální skenovací kalorimetrie MeSH
• kryoprezervace * metody   MeSH
• kryoprotektivní látky farmakologie   MeSH
• Rubus * fyziologie   růst a vývoj   MeSH
• vlhkost MeSH
• voda metabolismus   MeSH
• výhonky rostlin * fyziologie   MeSH
• vysoušení MeSH
• zmrazování MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• kryoprotektivní látky MeSH
• voda MeSH

Phenylarsonic acid is the parent compound of a group of derivatives that occur as anthropogenic environmental contaminants in both less toxic As(V) and much more toxic As(III) redox states. To elucidate the mechanisms underlying their enzymatic redox conversions, the activities of two flavin reductases, ArsH and FerA, from the soil bacterium Paracoccus denitrificans were compared. The stopped-flow data demonstrated that PhAs(V) oxidized dihydroflavin mononucleotide bound to ArsH, but not to FerA. This result proves that ArsH has some substrate specificity for organoarsenic compounds. Under aerobic conditions, both enzymes accelerated the oxidation of PhAs(III) in a catalase-sensitive manner, indicating that hydrogen peroxide acts as an intermediate. H2O2 was shown to react with PhAs(III) in a bimolecular (1:1) irreversible reaction. When exposed to blue light, flavin alone mediated rapid oxidation of PhAs(III) by O2. Photooxidation by flavin acted in concert with chemical oxidation by transiently accumulating H2O2. The described processes may be relevant in the context of arsenic ecotoxicology and remediation.

• Klíčová slova
• ArsH protein, Flavin, Hydrogen peroxide, Organoarsenicals, Photocatalysis, Redox reaction,
• MeSH
• arsenikové přípravky * chemie   metabolismus   MeSH
• flaviny * metabolismus   chemie   MeSH
• FMN-reduktasa * metabolismus   chemie   MeSH
• fotochemické procesy MeSH
• oxidace-redukce MeSH
• peroxid vodíku chemie   metabolismus   MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• arsenikové přípravky * MeSH
• diphenylarsinic acid MeSH Prohlížeč
• flaviny * MeSH
• FMN-reduktasa * MeSH
• peroxid vodíku MeSH