This study examines sorption kinetics for the extraction of ammonium ions from an aqueous solution under static conditions using 5 g of sorbent. The sorbent was obtained by calcining ash and slag waste accumulated in the ash dump following hydraulic ash removal. The initial concentrations of ammonium ions in the model solutions were 5, 20, 50 and 100 mg/dm³. The volume of the model solution was 50 cm³. For each initial concentration, the kinetic curves of the ammonium ion sorption at the sorption duration of 10, 30, 60, 90, 120, 150 and 180 min were obtained. The kinetic curves were processed using the Lagergren (pseudo-first order), Ho and McKay (pseudo-

second order), Morris-Weber (diffusion) and Elovich kinetic equations. It was demonstrated that all kinetic equations adequately describe the experimental data. The linear correlation of the equations was given. The Boyd equation was used to determine the limiting stage in the Morris–Weber model. It was established that the external diffusion mechanism is limiting for the sorption of ammonium ions by a calcined sorbent. The Lagergren model, with a coefficient of determination R² of 0.9801–0.9949, best described the experimental data on sorption kinetics. Sorption rate curves as a function of the adsorption value and sorption time were given. The latter are described by exponential and polynomial dependence according to the Lagergren model, polynomial dependence according to the Ho and McKay model and exponential dependence according to the Morris–Weber and Elovich models. The sorption rate was the highest at the initial stage of sorption for all dependencies, which is consistent with previous studies on the sorption of pollutants from aqueous solutions using various sorbents.

The paper considers the effect of a structure-forming agent (titanium dioxide) on the rheological characteristics of a polymer mixture based on low and high density polyethylene, taken in a 50/50 ratio. The titanium dioxide concentration was 1 wt%. The rheological behavior of melts of polymer composites was studied using a CEAST MF50 capillary rheometer (Instron, Italy) at temperatures of 190, 210, 230, 250 °С and loads of 3.8, 5.0, 10.0, 12.5, and 21.6 kg. The effect of temperature and shear stress on the regularity of changes in effective viscosity and shear rate has been established. According to the Arrhenius – Frenkel – Eyring model, the activation energy of the viscous flow of composites is determined. The “apparent” activation energy of the viscous flow varies within 16.04–33.10 kJ/mol for the initial polyethylene mixture and in the range of 6.96–33.10 kJ/mol for composites modified with a structurant based on a mixture of low and high density polyethylene. A universal temperature-invariant characteristic of the viscosity properties of polymeric materials has been constructed, which makes it possible, by extrapolating this dependence to the region of high shear rates, to predict the technological mode of their processing by injection molding and extrusion.

During the development of polymer science, attention has been attracted to different research areas. The current focus on polymer mixtures is due to their practical significance. Studying the physical and mechanical properties of polymer mixtures has led to a revision of existing basic concepts, the emergence of new research directions and the solution of practical problems. From this point of view, polymer mixtures are similar to copolymerization in achieving specific properties by combining different chemical structures. The use of polymer mixtures allows materials with the desired properties to be obtained at a faster rate than the synthesis of high-molecular compounds. In recent years, numerous studies have been published on the interaction of various polymers, particularly water-soluble and naturally occurring polymers that are safe for humans and the environment. The development of such materials is of great interest due to their high adhesive strength. These materials can be used to obtain polymer films with new valuable properties. This work investigates the potential of improving the thermomechanical and mechanical properties of films for use in construction as polymer biocidal additives by modifying polyhexamethylene guanidine hydrochloride with polyvinyl alcohol. Films based on a polymer-polymer mixture of polyhexamethylene guanidine hydrochloride and polyvinyl alcohol were used as a research object.

One of the most common elements present in naturally occurring waters, manganese is an essential trace element, whose daily intake requirement by the human body is around 5–7 mg.  While a lack of manganese in drinking water can lead to negative health consequences, a high manganese content in water and increased daily intake leads to the blocking of enzymes used in the conversion of inorganic iodine to organic, additionally changing inactive diiodothyronine into the active hormone thyroxine. The study investigates the possibility of using carbon sorbents having a microporous structure to change the manganese content in aqueous solutions. The adsorption capacity of One of the most common elements present in naturally occurring waters, manganese is an essential trace element, whose daily intake requirement by the human body is around 5–7 mg.  While a lack of manganese in drinking water can lead to negative health consequences, a high manganese content in water and increased daily intake leads to the blocking of enzymes used in the conversion of inorganic iodine to organic, additionally changing inactive diiodothyronine into the active hormone thyroxine. The study investigates the possibility of using carbon sorbents having a microporous structure to change the manganese content in aqueous solutions. The adsorption capacity of manganese significantly depends on the acidity of the medium. The highest adsorption value of manganese (II) cations is observed in a weakly alkaline medium (pH 7.5). Kinetic studies demonstrated the possibility of describing the interaction using a pseudo first-order equation. The reaction rate constant as calculated by graphical and computational variants was 0.067 s^-1. A functional assessment of the adsorption process can be represented by monomolecular adsorption isotherms, which are described by the classical Langmuir equation. The characteristic adsorption constant parameters were as follows: limiting adsorption value – 1.68 mmol/g; adsorption equilibrium constant – 0.979×10³ at a temperature of 298 K. Gibbs energy at 298 K is equal to – 7.41 kJ/mol. The study of the process at elevated temperatures of 308, 318 and 328 K indicates its exothermic nature. With heating, the limiting adsorption decreases.

Carotenoids represent a group of isoprenoid pigments whose high biological activity is not limited to their provitamin properties. Due to their ability to participate in redox reactions, carotenes are increasingly considered as promising compounds in the prevention and correction of cardiovascular and neurodegenerative disorders, as well as in oncology and the treatment of various other diseases. Carotenoids are widely used in the manufacture 

of food additives and dyes, feed for aquaculture, farm animals and poultry, as well as in so-called nutraceuticals and cosmetics. When formulating optimal feeding rations, vitamin A nutrition is often considered separately due to its vital role in normal growth, development, maintenance and reproduction. The main precursor of vitamin A is β-carotene, which naturally enters the body exclusively via vegetable-based provender. However, since the carotene contained in plant raw materials is an unstable compound, the use of feed additives containing β-carotene becomes relevant. In industry, carotenoids can be produced either by chemical or biological synthesis. However, the majority of carotenoids – 80–90% – are obtained by chemical synthesis. At the same time, public demand for sustainable production dictates the need to find alternative approaches for obtaining this valuable commodity. The article provides an overview of the main biotechnological methods for the production of carotenes using various microorganisms, including microalgae, bacteria and fungi, as well as analysing the effect of culture conditions on the yield of target pigments.

The study investigates the use of protatran compounds as growth stimulators for Bacillus thuringiensis bacteria, which are widely used as producers of biopesticides. Cultivation of the Bacillus thuringiensis strain subsp. kurstaki was carried out in a Luria-Bertani (LB) liquid medium. Protatrans (2-Me-C₆H₄OCH₂COO^- were added to the NN+(CH2CH2OH)3 (1), 4-Cl-C6H4 -SCH2COO-NN(CHCHOH) (2) and 4-Cl-CSOCHCOO NN+(CH2CH2OH)3 (3) media in concentrations of 1×10^-4–1×10^-8wt %. The LB medium without the addition of compounds 1–3 was used as a control. Cultures were incubated at a temperature of 30°C for 24 hours. The number of Bacillus thuringiensis cells was determined by serial dilution. The maximum growth was observed in a medium containing 1×10^-4wt % of protatran 3. The number of cells was almost 10 times (966.7%) higher than in the control. In media with 1×10^-5, 1×10^-6, 1×10^-7 and 1×10^-8 wt % of compound 3, the number of cells was 4–7 times higher than in the control (by 371.7–666.7%). Protatrans 1 and 2 had a positive effect on Bacillus thuringiensis, increasing the number of cells by 83–292% compared to control. Therefore, it was demonstrated for the first time that commercially available non-toxic protatran compounds in microconcentrations are powerful growth stimulators for the entomopathogenic bacteria Bacillus thuringiensis. This indicates the potential for significant improvement and cost reduction of biotechnology for the production of bacterial insecticides based on Bacillus thuringiensis, used in agriculture, forestry and homesteads to control harmful insects.

Although representative species of the Ochitaceae subfamily (Sedoideae) have long been used as medicinal plants, the biochemical composition of most species remains understudied. This hinders their use in pharmacology and medicine. This study quantifies the content of the main groups of biologically active substances in the aboveground part of the Sempervivoideae at the beginning and end of the vegetation period. Freshly harvested vegetative shoots of the following species (raw materials) were examined: Aizopsis aizoon (L.) Grulich, Aizopsis hybrida (L.) Grulich, Aizopsis kurilensis (Vorosch.) S. Gontch., Hylotelephium ewersii (Ledeb.) H. Ohba, Sedum acre L., Sedum album L., Sedum hispanicum L., Sedum reflexum L., Sedum rupestre L. and Sedum spurium M. Bieb. Conventional methods of phytochemical analysis were used. The solid content was determined by drying 1 g of raw materials to a constant weight. The amount of phenolic compounds, pectin substances and total sugars was determined by the spectrophotometric method in ethanolic extracts by calculating the indicators relative to the solid mass of the raw materials. Titrimetric analysis was used to determine the concentration of ascorbic acid in the wet weight of the raw material. The content of solid (7.22–18.98%), catechins (0.14–6.01 mg%), flavonols (0.59–3.11%), tannins (4.44–26.73%), pectins (0.14–3.51%), protopectins (3.10–11.82%), total sugars (10.25–57.96%) and ascorbic acid (43.4–94.4 mg%) was determined. The tendency to accumulate phenolic compounds, sugars and solids, along with a decrease in the content of pectin polysaccharides, by the end of the vegetation was revealed. The results indicate the potential for the cultivation of Sempervivoideae as a source of various bioactive compounds.

Fatty acids, as part of cell membranes, determine their fluidity and dielectric constant. In addition, they play an important role in human and animal nutrition. This work examines the composition and fatty acid content of dried higher aquatic plants from Lake Kotokel (Republic of Buryatia, Russia) and their potential as a raw material for 

the production of feed and biologically active food supplements. A modified Bligh-Dyer method was used to extract lipid fraction. Fatty acids in the form of their methyl esters were analysed by gas chromatography–mass spectrometry. Palmitic C16:0 acid was the main saturated fatty acid found in Myriophyllum sibiricum, Elodea canadensis, Persicaria amphibia and Potamogeton perfoliatus in Lake Kotokel. The main unsaturated acid found in plants, regardless of their type, was the α-linolenic C18:3-ω3 acid. In addition, a relatively high content of stearic C18:0, myristic C14:0 and pentadecanoic C15:0 acids was noted. Branched acids (i-C14:0, i-C15:0, i-C16:0, i-C17:0, i-C20:0, a/i-C15:0, a/i-C17:0 and 10Me-C16:0) and odd carbon numbered acids (C13:0, C15:0, C17:0, C19:0, C21:0 and C23:0) were identified. An analysis of the authors’ and literature data revealed that the studied species of higher aquatic plants in reservoirs in the Asian part of Russia are characterised by a high content of α-linolenic C18:3-ω3 (up to 56%) and a low content of oleic C18:1-ω9 (up to 1.81%) acids. The content of α-linolenic C18:3-ω3 acid in plants from reservoirs in the European part of Russia was lower (up to 42%), while that of oleic acid C18:1-ω9 was higher (up to 14%).

In the process of sprout formation, a seed undergoes a number of biochemical transformations, forming intermediate metabolites of macromolecules that offer biological activity, higher solubility and bioavailability, which are attractive for use in various food processing applications. The purpose of the study was to evaluate the properties of the product that remains following the separation of sprouts from sprouted pea seeds, as well as investigating the possibility of its use in food production. As the objects of the study, data on the germination time,content, structure and depth of proteolysis of legumin pea protein were considered on the example of Temp, Sofia, and Spartak varieties. The composition of the decomposition products of legumin following the separation of the sprout is mainly determined by the decomposition products of the protein edges. According to the calculated dependence based on the structural characteristics of the legumin protein and the direction of its proteolysis, a sprout formation time equal to 98 hours was determined, which corresponds to the experimental data (96 hours). The product obtained from sprouted pea seeds following the separation of sprouts differs significantly in protein and peptide content from flour obtained from ripe peas. This is due not only to the hydrolysis of starch, but also to the step-by-step hydrolysis of protein, which leads to an increase in the content of short-chain peptides, increasing the solubility of the protein component of the flour, but also requiring appropriate correction of their concentration when used as additives to various food products, especially in terms of liquid consistency.

The study set out to investigate the effect of different concentrations of copper ions on the composition of phytosterols of the vacuolar membrane (tonoplast) of beetroot (Beta vulgaris L.). To characterise the stress caused by the action of copper ions, a conductometric study of the permeability of cell membranes and the level of lipid peroxidation was carried out. The results demonstrate an increase in these indicators in beetroot tissues. Among tonoplast phytosterols, β-sitosterol, stigmasterol, campesterol, and cholesterol were studied. In cell membranes, these phytosterols perform a structural function, contributing to lipid microdomain formation, influencing plant growth and development, and participating in plant responses to stress. The study of the effect of copper ions on tonoplast phytosterols showed most of them to be occupied by the free form. In the presence of 100 μM copper, a significant increase in campesterol content was detected. The ratio of stigmasterol/β-sitosterol and 24-methyl-/ ethylsterol, which may influence the stress response of plants, is an important indicator of plant membrane health. The observed increases in the ratios of stigmasterol/β-sitosterol and 24-methyl-/ethylsterols can be explained in terms of mechanisms for regulating the functioning of the tonoplast under stress caused by copper ions. Thus, the obtained results may indicate the participation of cell membranes, including tonoplast, in the mechanisms of adaptation of beetroot tissue cells to stress caused by copper ions.

A study of the antibacterial properties of a non-polar extract of microalgae Chlorella sorokiniana on gram-positive bacteria is presented along with a determination of the minimum inhibitory concentrations of the mixture and the individual metabolites that make up the extract. A regular effect of illumination on the intensity of the antibiotic effect of non-polar microalgae extract on gram-positive bacteria is demonstrated. A mixture of substances extracted from disintegrated cells of the microalgae biomass Chlorella sorokiniana has an inhibitory effect on bacterial growth at a photosynthetically active radiation level of 100±6 μmol photons/(m²×s). The minimum effective amount of the extract is 330±11.09 µg. When analysing the chemical structure of the components of the non-polar fraction extracted from the cells of microalgae Chlorella sorokiniana, the composition of the non-polar extract was shown to include triacylglycerides, fatty acids, o-dialkyl monoglycerides and ethers of sterols or waxes, or trialkyl esters of glycerol. When studying the antibiotic properties of individual fractions of substances, triacylglycerides and fatty acids were found to have an antibiotic effect on gram-positive bacteria. In this case, the minimum effective amount of triacylglycerides is 400±13.37 μg, while that of fatty acids is 600±20.05 μg. The combined effect of a mixture of non-polar extract substances gives the most pronounced antibiotic effect on gram-positive bacteria at a photosynthetically active radiation level of 100±6 μmol of photons/(m²×s). Thus, an increase in antibacterial action was demonstrated when using a mixture of substances of the non-polar extract of microalgae Chlorella sorokiniana at a photosynthetically active radiation level of 100±6 μmol of photons/(m²×s).

Biologically active substances that confer antiviral, anti-tumour and antimicrobial effects, which are found among the components of plant raw materials, as well as the products of their chemical modification, are the subject of considerable research interest. These objects include tricyclic diterpenoids – extractives of wood of abietic and pimaric types (resin acids). The presence of two reaction centres (double bonds and a carboxyl group) in the structure of resin acids opens up a wide range of possibilities for synthesising useful compounds on their basis. One of the most promising areas for the study of resin acids and their derivatives consists assessing their fungicidal properties to inform their introduction into compositions as additives, as well as in the application of protective films to increase the resistance of composite building materials against the aggressive effects of microorganisms. In the present work, the fungicidal activity of the N-phenylimide of maleopimaric acid and its polyfluoroalkyl ethers synthesised by us was evaluated on the cells of the filamentous fungi Aspergillus niger, Alternaria alternata and Penicillium sp. by the rate of colony formation and growth. A comparative analysis of the biological activity of resin acids and their in silico derivatives was performed. According to the AntiBag Pred forecast, the test compounds having the maximum values of the probabilities of the presence and absence of each type of activity are characterised by the manifestation of antibacterial activity in relation to strains of gram-positive bacteria. The results of the predictive model are consistent with previous experimental data. However, AntiFun Pred data related to the calculation of fungicidal activity were not confirmed in vitro.

One of the actively developing areas in the current production of motor fuel components from renewable raw materials consists in the processing of vegetable oils using various catalytic processes. The object of research in this paper was rapeseed oil and the products of its processing on a hydrotreating catalyst. The choice of rapeseed oil as a raw material for processing is due to the large acreage it occupies on the territory of the Russian Federation as food industry, currently being produced mainly for export. The authors investigated a process of catalytic processing of rapeseed oil using a hydrotreating catalyst. The processing was carried out in a laboratory catalytic unit at a temperature of 375 °C, a pressure of 7 MPa, and a volume feed rate of 1 h^-[1]; the hydrogen consumption was 2×10^-4 m³/h Physicochemical and low-temperature properties were determined for the feedstock and catalytic processing product. In addition, the component composition was determined for the resulting catalytic reprocessing product. The main directions of chemical transformations of rapeseed oil components into hydrocarbons on a hydrotreating catalyst are considered. The possibility of using rapeseed oil as a feedstock for producing fuel hydrocarbons – in particular n-alkanes, iso-alkanes and alkenes, which are promising raw materials for the production of motor fuel components – is substantiated. 

The study set out to extract various types of hydrocarbons from model fuels using deep eutectic solvents based on glycerol. These solvents were synthesised by mixing glycerol as acting as a hydrogen bond donor with ammonium chloride or triethylammonium acetate [tea] [AcO]^- acting as a hydrogen bond acceptor at room temperature in a volume ratio of 1:6. A mixture of n-decane and n-hexadecane was selected as components of the model fuel. For the extraction of mixtures of benzene, ethylbenzene (5%), p-, m-, o-cresol, fluorenone (3.5%) and petroleum acids (25%), these deep eutectic solvents were used at room temperature, as well as at a temperature of 60°C, and at atmospheric pressure. Extraction efficiency was evaluated by ^[1]NMR spectroscopy. The results demonstrated the complete single-stage extraction of p-, m- and o-cresols from the model fuel using the studied deep eutectic solvents. A deep eutectic solvent based on glycerol and triethylammonium acetate was found to have the highest extraction efficiency. The recovery rates for benzene, ethylbenzene, and fluorenone at room temperature are achieved in 3 hours of stirring (75, 25, and 53%, respectively). M- and o-cresols were fully recovered in 1 hour in a single step using a deep eutectic solvent based on triethylammonium acetate, while complete extraction of aromatic acids from a mixture of petroleum acids in model fuel was achieved using a deep eutectic solvent obtained by mixing ammonium chloride and glycerol.

The purpose of the study was to determine the qualitative and quantitative amino acid composition of pollen Pinus sylvestris L. and Pinus sibirica Du Tour. Pine pollen was collected in June 2021 at natural sites on the southeastern coast of Lake Baikal. The mass fraction of crude protein was determined by the Kjeldahl method; the protein composition and individual amino acid content were determined by high-performance liquid chromatography with post-column modification of ninhydrin on an LA8080 automatic analyser (Hitachi, Japan). The crude protein content of the pollen was 14.38–15.94%. Pine pollen protein is shown to contain 17 amino acids, including 9 essential amino acids: valine, isoleucine, leucine, threonine, methionine, phenylalanine, lysine, histidine, and arginine. The content of the sum of amino acids was 141.4–156.5 mg/g, including essential amino acids 45.9-48.4%. The following amino acids are dominant in Pinus sylvestris and Pinus sibirica pollens (mg/g): monoaminodicarboxylic acids – glutamic (21.3–24.2) and aspartic (13.0–14.2), diaminocarboxylic acid arginine (17.0–17.4) and heterocyclic amino acid proline (14.7–16.2). The obtained results can be useful in the development of drugs and biologically active additives based on pollen Pinus sylvestris and Pinus sibirica, which, due to the presence of the above amino acids, have a nootropic, immunomodulatory, cardiac stimulating, and detoxifying effect.