Oxydifficidin is a natural polyketide antibiotic that is a long-known ribosome-targeting antibiotic that inhibits protein synthesis. In this paper, we describe Bacillus velezensis strain EV17 and compare its complete genome sequence with that of the previously characterized strain K-3618 and the difficidin biosynthetic gene cluster (BGC) combined with mass spectrometry, to elucidate the production of oxydifficidin by these strains. Isolated oxydifficidin was determined to increase generalized inhibition of translation at each step of protein biosynthesis using toeprinting and small fluorescent peptide assays. In previous studies, it has been demonstrated that oxydifficidin targets L7/L12 protein. Although spontaneous mutations in ribosomal protein L7/L12, located relatively close to the thiostrepton binding site on uL11, confer resistance to oxydifficidin, our data show that oxydifficidin binding does not interfere with thiostrepton, thereby refining previous findings about its putative ribosomal target. We show that this compound does not affect eukaryotic translation and has no toxic effect on eukaryotic cells. These facts are important to further investigate its potential as a bioprotectant against phytopathogens or even as a therapeutic activity.

Oxydifficidin is a natural polyketide antibiotic that has long been recognized as a ribosome-targeting agent that inhibits protein synthesis. In this paper, we describe Bacillus velezensis strain EV17 and compare its complete genome sequence with that of the previously characterized B. velezensis strain K-3618 and the difficidin biosynthetic gene cluster (BGC) combined with mass spectrometry to elucidate the production of oxydifficidin by these strains. Toeprinting and small fluorescent peptide assays showed that isolated oxydifficidin induces a generalized inhibition of translation at every step of elongation in protein biosynthesis. In previous studies, it has been demonstrated that oxydifficidin targets bL12 protein. Although spontaneous mutations conferring resistance to oxydifficidin in ribosomal protein bL12 located relatively close to the thiostrepton binding site on uL11, our data show that oxydifficidin binding does not interfere with thiostrepton, thereby refining previous findings about its putative ribosomal target. We are the first to show that this compound does not affect eukaryotic translation and has two orders of magnitude lower effect on eukaryotic cells compared to bacteria. These facts are important to further investigate its potential as a bioprotectant against phytopathogens or even as a therapeutic agent.

Antibiotic resistance has been and remains a major problem in our society. The main solution to this problem is to search and study the mechanisms of antibiotic action. Many groups of secondary metabolites, including antimicrobial ones, are produced by the Actinomycetota phylum. The actinobacterial strains isolated from habitats that have not been well studied are of great interest. Due to high resource competition, antibiotics are now considered a ‘trump card in the game of life’ due to their presence in natural substrates with limited nutrients. Potentially, strains isolated from such habitats can be producers of novel or poorly studied antibiotics. In the current research, we identified the strain Streptomyces sp. AP22 from the soils of the Akhshatyrsky Gorge, which is capable of producing pentalenolactone. This study describes the phenotypic and morphological characteristics of Streptomyces sp. AP22 and its biological activity. Pentalenolactone is a known inhibitor of glyceraldehyde-3-phosphate dehydrogenase (GAPDH), an important enzyme involved in glycolysis. We identified a previously unknown mutation in the gapA gene encoding glyceraldehyde-3-phosphate dehydrogenase that confers resistance to this antibiotic compound. This antibiotic is not used in clinical practice, so its application as a selectable marker will not lead to the creation of pathogens resistant to clinically relevant antibiotics. In this case, the selectable marker is based on a genetic construct containing the glyceraldehyde-3-phosphate dehydrogenase gene with a resistance mutation. The use of this selectable marker can be applied to various genetic and molecular techniques, such as cloning and transformation. This can help to facilitate genetic and molecular biology studies of strains resistant to standard selectable markers such as kanamycin or ampicillin.

Whole-genome sequence of ET2 strain, isolated from the roots of leafless orchid, constitutes a single circular chromosome of 3,604,840 bp (69.44% G + C content). BLAST+-based average nucleotide identity (ANIb) and digital DNA-DNA hybridization values indicate that ET2 may be a novel Microbacterium species. Genes putatively involved in plant-microbial interactions were predicted.

This article addresses the issues surrounding the formation of the domestic tax culture in Russia. These issues are largely attributed to the state of “cultural tax shock” experienced by the Russian population in the post-perestroika period. However, even in Soviet times and earlier, a characteristic feature of Russian mentality known as “tax nihilism” was observed. The current state of tax culture can be characterized in two aspects: by examining the level of tax literacy among the population and taxpayers’ trust in tax authorities. Particular attention should be paid to youth in the formation of tax culture due to their detachment from the consequences of the societal transformation processes at the end of the last century. The article analyzes ways to increase the level of tax literacy among Russian schoolchildren. However, the problem of tax literacy among Russian students persists, coupled with the increasing prevalence of secondary employment among them. Measures to enhance public trust in tax authorities are also considered. The article emphasizes the role of developing the theoretical basis of tax culture, which requires attention not only to developments in traditional fields of law and economics but also in social research on fiscal sociology and the philosophy of taxation. In conclusion, the formation of tax culture in Russia faces multifaceted challenges stemming from historical legacies, societal perceptions, and educational gaps. By addressing these issues holistically, Russia can progress towards cultivating a more informed and cooperative tax culture among its populace.

The effect of a high-power ion beam of nanosecond duration on the phase composition and morphology of the surface of aluminum composite material SAP-2 is studied. It is found that after irradiation with a high-power ion beam under all irradiation modes used in the experiments no changes in the phase composition are observed. However, the observed shifts and broadening of the diffraction peaks from irradiated samples indicate the formation of residual stresses and transformation of the initial dislocation structure. The observed decrease in the dislocation density results in a decrease in the microhardness of SAP-2 irradiated at current densities of 50 and 100 A/cm2. It is shown that the increase in the ion-current density leads to an increase in the oxygen fraction in the surface layer of SAP-2, which is apparently associated with the partial evaporation of aluminum and an increase in the concentration of inclusions of Al2O3, which is part of the material. A nonlinear character of the dependence of the average ratio of the oxygen content to aluminum on the ion-current density of the beam is observed, the maximum value of which is recorded upon irradiation with a beam-current density of 100 A/cm2. Intense heating of the SAP-2 surface under ion-beam irradiation leads to changes in the dispersion of Al2O3 inclusions on the irradiated surface. The maximum coagulation of Al2O3 particles is found in the case of irradiation by a high-power ion beam with a current density of 100 A/cm2.

Hot springs are inhabited by specific microbial communities which are reservoirs of novel taxa. In this work strain 4228-RoLT was isolated from the Solnechny hot spring, Uzon Caldera, Kamchatka. Cells of the strain 4228-RoLT were Gram-negative rods forming multicellular filaments. The strain grew optimally at 60 °C and pH 7.0 and fermented various organic compounds including polysaccharides (microcrystalline cellulose, xylan, chitin, starch, dextrin, dextran, beta-glucan, galactomannan, glucomannan, mannan). Major fatty acids were iso-C17:0, C16:0, C18:0, C20:0, iso-C19:0, anteiso-C17:0 and C22:0. Genome of the strain was of 3.25 Mbp with GC content of 54.2

Composite films containing poly(vinyl alcohol) filled with different amounts of graphene oxide (2 and 4 wt

The genome of Thermomicrobium sp. strain 4228-Ro, an aerobic thermophilic bacterium isolated from a Kamchatka hot spring, was sequenced and analyzed. The genome assembly comprises 13 contigs with a total length of 3,068,448 bp. Genome analysis revealed the pathway of aerobic utilization of sugars, which was corroborated by growth experiments.

The effect of a high-power ion beam (HPIB) of nanosecond duration on polycrystalline magnesium is investigated. A decrease in the content of magnesium oxide on the surface is found with an increase in the current density of the ion beam and the number of pulses. At a current density of 150 A/cm2, oxide is found only at the edges of crater formations. The observed cracks in the crater zone indicate the achievement of critical values of residual stresses under the irradiation modes used in the experiment. The analysis of changes in the grain structure show that irradiation with a HPIB leads to a decrease in the grain size by a factor of 1.6. An increase in the microhardness values is observed for magnesium samples irradiated by a HPIB with a current density of 50 and 100 A/cm2 by three pulses by 1.3 and 1.4 times, respectively, for an indenter penetration depth of up to 6 μm and a current density of 100 A/cm2 at large depths by 1.6 times. Two characteristic maxima of microhardness are found at depths of ~6 and ~9 µm for magnesium samples irradiated with a HPIB with a current density of 150 A/cm2 by three pulses. Possible mechanisms for the refinement of the grain structure and changes in the microhardness in magnesium upon HPIB irradiation are discussed.

Nanopore sequencing (ONT) is a new and rapidly developing method for determining nucleotide sequences in DNA and RNA. It serves the ability to obtain long reads of thousands of nucleotides without assembly and amplification during sequencing compared to next-generation sequencing. Nanopore sequencing can help for determination of genetic changes leading to antibiotics resistance. This study presents the application of ONT technology in the assembly of an E. coli genome characterized by a deletion of the tolC gene and known single-nucleotide variations leading to antibiotic resistance, in the absence of a reference genome. We performed benchmark studies to determine minimum coverage depth to obtain a complete genome, depending on the quality of the ONT data. A comparison of existing programs was carried out. It was shown that the Flye program demonstrates plausible assembly results relative to others (Shasta, Canu, and Necat). The required coverage depth for successful assembly strongly depends on the size of reads. When using high-quality samples with an average read length of 8 Kbp or more, the coverage depth of 30× is sufficient to assemble the complete genome de novo and reliably determine single-nucleotide variations in it. For samples with shorter reads with mean lengths of 2 Kbp, a higher coverage depth of 50× is required. Avoiding of mechanical mixing is obligatory for samples preparation. Nanopore sequencing can be used alone to determine antibiotics-resistant genetic features of bacterial strains.

A new delivery system has been developed that combines liposomes and silica nanocapsules. It was found that in the presence of cationic unilamellar liposomes, silica nanocapsules are instantly coated with a lipid bilayer. In contrast, cationic stealth liposomes modified with polyethylene glycol can adsorb on the surface of silica to form multi-liposomal composites in which the liposomes remain intact.

Composite films containing poly(vinyl alcohol) filled with different amounts of graphene oxide (2 and 4 wt%) were prepared by the solution casting technique, and the mechanical properties of the resulting materials were modified with different amounts of glycerol as a plasticizer. Two series of pure poly(vinyl alcohol) and graphene oxide-loaded films with fixed amounts of water were used for modification with glycerol, since water can also serve as a plasticizer for poly(vinyl alcohol). The morphology and physical properties of the plasticized and non-plasticized composites were studied; tensile tests were performed to investigate and compare their mechanical properties. Glycerol addition does not affect the excellent compatibility of the filler with the polymer matrix and uniform distribution of graphene oxide in poly(vinyl alcohol). For poly(vinyl alcohol)/graphene oxide films an increase of the Young's modulus and yield stress was found with an increase of the filler content; the Young's modulus for poly(vinyl alcohol) filled with 4 wt% of graphene oxide is almost two times higher than that of the pure polymer. Simultaneously, a sharp decrease of the elongation at break from 80% for pure PVA to about 5% for the PVA/GO composite with 4 wt% of GO is observed, and the film's brittleness dramatically increases. It was shown that the addition of glycerol to the composite films leads both to the Young's modulus decrease and tensile energy at break increase; here the Young's modulus decreases by 18 times after addition of 20 wt% of glycerol to the poly(vinyl alcohol) film filled with 4 wt% of graphene oxide. Thus, the use of plasticizer results in a significant increase of the ductile properties of graphene oxide filled poly(vinyl alcohol) composite films, and the higher the water content in the composite film, the more drastic the increase of the ductile properties observed.

The change in the phase and elemental composition of the surface layers of copper and its alloys, brasses LS59-1, L63, and bronze BrAZh9-4, preliminarily irradiated with a high-power ion beam, after oxidation in air at 400°C is studied. It is shown that depletion of the brass surface by zinc under irradiation with a high-power ion beam does not lead to a noticeable increase in the oxidation of brass during thermal annealing in air due to the diffusion of Zn from the volume to the surface. The annealing of high-power ion-beam-irradiated copper under similar conditions does not change the composition of oxidation products, and the phase ratio is determined by the duration of annealing. For BrAZh9-4 bronze irradiated by a high-power ion beam, enrichment of the surface with copper leads to the intensification of oxidative processes. Possible mechanisms for the observed changes in copper and its alloys are considered.

Thin conductive films have been obtained via dehydration and reduction of composite films based on polyvinyl alcohol and graphene oxide. Composition and structure of the nanocomposites as well as the features of heat-induced reduction and electroconductive properties of the products have been analyzed. It has been shown that dehydration of polyvinyl alcohol leads to the formation of additional contacts between the filler particles and significantly enhances the conductivity.

The multi-liposomal conjugate with encapsulated enzyme laccase is described, capable of releasing the payload when changing the temperature. For this, thermosensitive cationic microgels were synthesized, differing in the molar content of cross-linker from 2 to 8 mol%. The microgels collapsed when heated beyond the volume phase transition temperature (VPTT) of 38-40 degrees C, while the degree of the surface area contraction (phi) decreased with increasing the cross-linker content. At lower temperature, each swollen microgel particle, ca. 320 nm in diameter, adsorbed about 200 intact 50 nm anionic liposomes. Over VPTT, the liposomes disrupted and released their payload that was visually detected via a color "development" of a loaded into liposomes laccase substrate in the surrounding solution: the higher phi the more released enzyme and the higher colored product concentration. So, the correlation between the microgel cross-linking degree and the amount of released liposome payload was demonstrated for the first time. The results we have obtained are of interest for constructing drug carriers, catalysts and diagnostic systems.

Composite films were prepared using poly(vinyl alcohol) (PVA) and graphene oxide (GO) by solution casting technique, and their morphology, physical, and mechanical properties were studied. The hexagonal array of diffraction peaks reveals that GO is uniformly distributed in the polymer matrix, indicating the excellent compatibility of the filler with the polymer. GO incorporation does not change PVA degree of crystallinity, but increases the thermal stability (the temperature of degradation) of the polymer. For PVA/GO composite film with 4wt% of the filler, the tensile strength as well as the Young's modulus increases compared to that of the neat PVA film. At the same time, the GO addition led to a sharp decrease in the elongation at break of the sample. In order to improve the plasticity of the composite film, cold rolling processing of the composite PVA/GO film was performed which is known to suppress the tendency of nanocomposite to brittle fracture.

The fracture of surface layers of alumina ceramic (polycor) under the action of a high-power ion beam of nanosecond duration is investigated. The characteristic features of such fracture are determined. An estimation of the thickness of breakaway fragments of the surface layer of the ceramics gives values in the range from 4 to 12 μm at single high-power ion beam irradiation with a current density of 150 A/cm2. Oxygen depletion in the surface layer of the ceramics is established. The effect of irradiation on the structural-phase state of the ceramics is considered. The possible mechanisms of the observed fracture are discussed.

Chemical transformations in the course of heat treatment of polyacrylonitrile films containing highly dispersed multiwalled carbon nanotubes have been analyzed. It has been shown that the introduction of the nanotubes results in the cyclization reaction completeness at lower temperature in comparison of the pristine polyacrylonitrile, and the formed product has more regular structure.