Addition Of Acid Research Articles

Direct colorimetric detection of triacetone triperoxide explosive by hydroxylamine-mediated fenton chemistry catalyzed by goethite nanoparticles

Due to the absence of nitro groups or aromatic structures in its structure, spectrophotometric methods that can directly determine triacetone triperoxide (TATP) are absent. In the proposed study, a molecular spectroscopic sensor was developed based on the decomposition of TATP by hydrolysis without the addition of external acid, allowing the direct determination of TATP. The detection principle of the developed sensor is based on the decomposition of TATP by the hydrochloric acid formed as a result of the reaction of TATP with hydroxylamine hydrochloride, taking advantage of the solubility of TATP in acetone, and the hydrogen peroxide formed as a degradation product to form hydroxyl radicals catalyzed by goethite nanoparticles. The formed hydroxyl radicals, thanks to their strong oxidation properties, oxidized N,N-dimethyl-p-phenylenediamine (DMPD) to the pink-colored DMPD•+ radical cation, and the direct determination of TATP was performed by measuring the absorbance of the colored product formed. Thus, a chemo-cybernetic sequence of reactions is proposed for intact TATP assay in a circular self-sustained system, where the reactants at a given step of reactions are supplied by the products of a previous step. By applying the developed method to TATP samples prepared in acetone, absorbances due to DMPD•+ were read at 554 nm to evaluate the results. A calibration curve was created between absorbance versus TATP concentration within a final range of 10 – 33 mg L-1. The limit of detection (LOD) and limit of quantification (LOQ) of the developed TATP method were 3.3 mg L-1 and 10.8 mg L-1, respectively. Five replicate measurements were performed to determine the intra-assay and inter-assay precision of the spectrophotometric determination of TATP, and the relative standard deviations (RSD %) for TATP were found as 2.70 % and 3.76 %, respectively. Interference analysis was carried out to see the effects of ions commonly present in soil/groundwater, and of the substances used as camouflage materials due to their color and appearance similarity to TATP. The selectivity of the method toward TATP was investigated by examining the analyte recovery from explosive mixtures. The developed method was validated against a reference GC–MS method using TATP-contaminated soil samples, and the results were compared statistically.

Effect of a thiazole derivative on the activity of antioxidant enzymes in murine lymphoma cells

Previous in vitro studies have demonstrated a pronounced cytotoxic effect of the thiazole derivative N-(5-Benzyl-13-thiazole-2-yl)-35-dimethyl-1-benzofuran-2-carboxami­de (BF1) on tumor cells. Additionally, it has been determined that scavengers of reactive Oxygen species (ROS) significantly reduce the cytotoxic effect of BF1. In this study, the influence of BF1 on the activity of superoxide dismutase (SOD) and catalase (CAT), both normally and in the presence of ascorbic acid, in mouse Nemeth-Kellner lymphoma (NK/Ly) cells has been studied to evaluate the possible role of antioxidant activity during the action of this substance. The experiments were performed using nonlinear male mice weighing 20–30 g. Intraperitoneal inoculation of 10–15 million cancer cells into the mice induced the ascites form of lymphoma. The thiazole derivative (BF1) was dissolved in dimethyl sulfoxide and added to the test samples at 1, 10, and 50 μM final concentrations. Superoxide dismutase (SOD) and catalase (CAT) activities were determined spectrophotometrically in a homogenate of the lymphoma cells after incubation with the drug for 30 minutes. The baseline level of SOD in the lymphoma of the mice was 0.33±0.02 activity units/min×mg protein. BF1 significantly increased the enzyme activity by 35 % and 29 % at concentrations of 10 (p<0.01) and 50 μM (p<0.05), respectively. The baseline level of CAT activity was 4.61±0.17 nmoles H2O2/min×mg protein, and this significantly decreased by 15 % (p<0.05) and 20 % (p<0.01) following the action of the thiazole derivative at a concentration of 10 and 20 μM, respectively. The increase of SOD activity, coupled with a decrease or absence of changes in CAT activity, may be cytotoxic to cancer cells. Simultaneously, upon the addition of ascorbic acid as a scavenger of ROS to the environment, the activities of SOD and CAT did not change under the action of BF1 at any of the investigated concentrations. Therefore, the effect of the thiazole derivative BF1 has been canceled in the presence of ROS scavengers in the environment. This may indicate the dependence of the cytotoxic effect of BF1 on the presence of ROS in tumor cells.

Transfersomal serum loading amniotic mesenchymal stem cells metabolite products with hyaluronic acid addition for skin regeneration in UV aging-induced mice.

Amniotic Mesenchymal Stem Cells Metabolite Products (AMSC-MP) contain growth factors that benefit human health. This study aims to evaluate the use of transfersomal serum (Trans) with hyaluronic acid (HA) addition to deliver large molecules of AMSC-MP for skin regeneration. Trans is composed of L-α-phosphatidylcholine and surfactants, i.e., sodium cholate (SC) or stearylamine (SA), at the weight ratio of 85:15, prepared by the thin film method with or without HA addition. The results showed that HA addition increased the particle size of Trans-SA and Trans-SC, from 261.9 ± 1.9 and 105.3 ± 0.9 nm respectively, to 317.7 ± 9.1 and 144.3 ± 0.8 nm for Trans-SA-HA and Trans-SC-HA. In contrast, no significant changes in the zeta potential occurred. The relative deformability indexes of Trans-SA, Trans-SA-HA, Trans-SC, and Trans-SC-HA compared to liposome were 0.43 ± 0.09, 0.46 ± 0.09, 1.58 ± 0.17, and 1.40 ± 0.17 respectively. The addition of HA successfully increases the in vivo skin hydration, collagen density, and number of fibroblast cells, reflecting the capacity for skin regeneration in UV-induced aged mice. Furthermore, no erythema or skin rash was observed at the 24-hour post-topical application sites. AMSC-MP transfersomal serum with HA addition successfully enhanced skin regeneration and proved safe during the in vivo study using UV aging-induced mice models, thereby enabling its potential use as skin-aging therapy.

The addition of 5-aminolevulinic acid to HBSS protects testis grafts during hypothermic transportation: a novel preservation strategy

The addition of 5-aminolevulinic acid to HBSS protects testis grafts during hypothermic transportation: a novel preservation strategy

Arsenite removal by using ZnAlFe mixed metal oxides derived from layered double hydroxides.

ZnAlFe mixed metal oxides (ZnAlFe-MMOs) were synthesized from layered double hydroxides (LDHs) prepared by the coprecipitation method at pH 9 using an initial weight composition of Zn2+ = 75%, Al3+ = 15% and Fe3+ = 10%, with or without the addition of citric or oxalic acid. The solids were calcined at 400 °C to obtain the respective MMOs, which exhibited relatively high specific surface areas (165.3 - 63.8 m2 g-1) and semiconductor properties active in the visible region (bandgap values (Eg) of 2.42 - 1.77 eV). The synthesized materials were tested for the removal of trivalent arsenic by adsorption and by photocatalysis under visible light irradiation (λ ≥ 420 nm). The best removal of As(III) by adsorption (65.9%) and by photocatalysis (99.9%) was obtained with the ZnAlFe-MMOs prepared in the absence of organic acids. The XPS results indicate the coexistence of As3+ and As5+ over ZnAlFe-MMOs after the photocatalytic reaction and also confirm the formation of Fe2+ sites on the hematite surface that enhances the removal of As(III). Raman measurements confirmed that, in the photocatalytic experiments, As is largely retained as As(V) on ZnAlFe-MMOs, bound to Fe. The results of fluorescence of 7-hydroxycoumarin suggest that the photocatalyst produces HO•, which can be the main species for As(III) oxidation under UV-Vis irradiation. Moreover, ZnAlFe-MMOs exhibited a good reusability after regeneration making ZnAlFe-MMOs a promising material for arsenic decontamination in polluted water.

Research on technological process for production of muskmelon juice (Cucumis melo L.)

Abstract The effects of hydrolysis of muskmelon pomace on fruit juice recovery efficiency, transmittance, total phenolic content, total ascorbic acid content, total flavonoid content, and total carotenoid content have been studied. The aim of this study was to evaluate the potential use of pectinase enzyme in the hydrolysis process, specifically looking at the effects of pH, temperature, time, and enzyme concentration on the production of effective muskmelon juice. Additionally, the optimal mixing ratio of ingredients such as melon juice content, Brix level, citric acid, and additives (pectin, sodium carboxymethyl cellulose [CMC], xanthan gum) was investigated to create a high-quality muskmelon juice product. The results showed that using a pectinase enzyme concentration of 0.2%, a pH of 5.0, and a hydrolysis temperature of 45°C for 120 min resulted in a muskmelon juice product with a hydrolyzed juice content of 20%, a Brix level of 12%, and a citric acid addition rate of 0.04%. The addition of xanthan gum at a rate of 0.03% also contributed to the desired flavor and color of the juice. These findings provide valuable insights for the development of effective muskmelon juice processes.

Printing with Natural Dye Extract from Japanese Knotweed Leaves

AbstractInvasive alien plants are detrimentally displacing native plant species and pose a challenge in terms of how their overgrowth can be utilized effectively. In our study, the leaves of one of the world’s worst invasive species, Japanese knotweed, were used to produce a green natural dye. This dye was screen-printed onto various substrates, including cotton and polyester fabrics, commercial cellulose papers, and innovative papers made from the stems of Japanese knotweed. The printed substrates were evaluated using color measurements and fastness properties. The aim of the study was also to investigate the influence of additives in the printing inks, such as sodium carbonate, citric acid, copper and aluminum sulfates, on the color and fastness properties of the prints. The colors of the prints obtained varied, ranging from primarily yellowish-green to brownish-yellow with the addition of citric acid, orange-brown with sodium carbonate, orange-yellow with aluminum sulfate, and brown with copper sulfate. The prints had excellent fastness to dry rubbing and moderate fastness to light. The prints of lower and medium dye concentrations on fabrics had very good fastness to wet rubbing and wet ironing, and on cotton even good fastness to washing. The additives in the printing inks, such as sodium carbonate and metal sulfates, reduced the abrasion resistance of the prints on paper and the wet fastness of the prints on fabrics, but only the metal sulfates had a positive effect on the light fastness of the prints.

Exploring the Chemistry of Ruthenium Complexes with a Bidentate Barbiturate‐Imidazo[1,5‐a]pyridinylidene Ligand

A novel reactivity of 5‐barbiturate imidazo[1,5‐a]pyridinium 1∙H with [Ru(2‐methylallyl)2(COD)] was explored which led to the formation of an uncommon, zwitterionic complex [Ru(1’)(1∙H)], composed of the NHC ligand 1’, cyclometallated at one ortho‐methyl position of the N‐mesityl substituent, and the zwitterionic precursor 1∙H. Barbiturate moieties coordinate either through a η3 mode or through coordination of the anionic oxygen atom to ensure the coordination saturation and stability to the complex. The addition of pivalic acid results in the protonolysis of the Ru‐Calkyl bond and demetallation of the N‐mesityl, while triphenylphosphine and pyridine are able to displace the rather labile 1∙H ligand. Attempts to incorporate an alkylidene fragment from these complexes led to the isolation of a rare complex 7 bearing an alkylidene tethered to a η5‐cyclopentadienyl ligand formed by phenylacetylene tetramerization.

Succinic Acid Improves the Metabolism of High-Fat Diet-Induced Mice and Promotes White Adipose Browning

Succinic acid plays a crucial role as an essential intermediate in the mitochondrial tricarboxylic acid cycle in mitochondria. In recent years, growing evidence has supported the the important role of succinic acid in fat metabolism. Therefore, we aimed to investigate the effects of succinic acid on adipose tissue metabolism and insulin sensitivity in high-fat diet (HFD)-induced obese mice and try to explore its potential mechanism. We found that the addition of succinic acid (40 mM) to drinking water inhibited the hypertrophy of inguinal white adipose tissue (iWAT) in HFD-induced mice. Furthermore, succinic acid supplementation enhanced insulin sensitivity and improved their glucose tolerance in obese mice. Interestingly, succinic acid supplementation improved lipid metabolism in HFD-fed mice, as shown by decreased serum levels of TG, TC, LDL-C, and increased HDL-C. In addition, succinic acid supplementation increased the expression of browning markers and mitochondria-related genes in iWAT. Further studies showed that the addition of succinic acid to drinking water promotes the browning of iWAT by activating the PI3K-AKT/MAPK signaling pathway. These results suggest that succinic acid has the potential to be used as an effective component for dietary intervention and may, therefore, play an important role in ameliorating and preventing obesity and associated metabolic diseases caused by HFD.

Nitrogen Doped Carbon Quantum Dots as Fluorescence "Turn-Off-On" Sensor for Detection of Fe3+ Ions and Ascorbic Acid in Moringa oleifera and Citrus Lemon.

In recent year, the uses of carbon quantum dots (CQDs) have increased in many fields. Herein we report, synthesis of fluorescent nitrogen doped carbon quantum dots (N-CQDs) by simple and ecofriendly hydrothermal method. The as-synthesized N-CQDs were characterized by various techniques and the quantum yield was also calculated. Then, application of N-CQDs were performed as a sensor for detection of ferric ions (Fe3+) based on static quenching mechanism (turn-off) which occurred due to formation of non-fluorescent complex between N-CQDs and Fe3+ ions. Interestingly, fluorescence intensity of quenched N-CQDs has been significantly recovered (turn-on) by addition of ascorbic acid (AA). The recovery mechanism is based on the redox reaction between Fe3+ ions and AA. Thus, N-CQDs has been used as fluorescence "turn-off-on" sensor for detection of Fe3+ ions and AA. Further this detection system is used for detecting Fe3+ ions in Moringa oleifera and AA in citrus lemon.

DRILLING MUD THINNER BASED ON TECHNICAL LIGNOSULFONATES FROM WASTE OF CATALYST PRODUCTION

The article presents the results of research on obtaining liquid thinners for drilling muds from waste generated at one of the technological stages in the production of sulfocationic catalysts from technical lignosulfonates.During the production of heterogeneous sulfo-cationic sorbents and catalysts from technical lignosulfonates, acidic waters containing low-molecular-weight fractions of lignosulfonates, residues of hemicellulose hydrolysis products, water-soluble, and extractive substances are generated at the stage of washing off the residual acid. One of the ways to utilize the generated waste could be its further processing into new reagents. Therefore, the aim of this work was to develop a formulation of a thinner based on the generated waste and study its effectiveness in typical drilling muds. A dry industrially produced lignosulfonate was used as a reference reagent.The possibilities of using the resulting liquid waste to obtain highly effective thinners for drilling muds based on lignosulfonates are shown. It is revealed that the resulting reagent reduces the rheological parameters of the drilling mud, is comparable in effectiveness to dry industrially produced lignosulfonate (0.5 % by weight and 1 % by weight), and is technologically easy to use. In fresh water solutions, the modified form of the reagent with the addition of oxyethylidenediphosphonic acid is more effective, while in mineralized solutions the unmodified form is more effective.

Closed-Loop Process of Extracting and Separating Zinc Impurities from Industrial Cobalt Products—Pilot Test Study

The cobalt-containing products of an enterprise were selected as the object of this study. The separation effect of Cyanex 272 on Zn and Co was studied through a pilot test. The results showed that Cyanex 272 had a high extraction rate for Zn at pH 3–3.4, up to 99.8%. The extracted Zn2+ was enriched in the organic phase, and the Zn2+ in the organic phase was extracted back into the aqueous phase in the stripping stage by adding strong acid. Addition amounts of strong acid of 50 g·L−1, 80 g·L−1, and 100 g·L−1 were set. The results showed that the addition amounts of 80 g·L−1 and 100 g·L−1 could significantly reduce the pH of the back-extraction solution and effectively enrich Zn2+ in the solution. There was a large amount of Zn2+ in the back-extraction solution, which could be used twice to prepare zinc carbonate products through neutralization and precipitation. By comparing the extraction effect, economic cost, and resource loss under different strong acid addition amounts, it was found that the 80 g·L−1 strong acid addition amount was more suitable for the actual production process. This study provides data support and practical evidence for the selection of industrial extraction process parameters for Zn2+ separation in actual cobalt products.

Synthesis of a Hard Anodic Oxide Coating with a Structure Allowing for Its Modification by Nanoparticles

A hard anodic oxide coating’s characteristic porous structure allows for its modification by the incorporation of nanoparticles. However, achieving an appropriate microstructure requires an optimal pore arrangement and shape, which is influenced by the electrolyte composition, current densities, temperature, and processing time. To achieve pores with a diameter of about 50 nm and the most regular structure, a range of these parameters were tested. Using a two-stage manufacturing process had a beneficial effect on increasing the microporosity of the coating. The addition of phthalic acid at 0 °C did not increase the pore diameter, but allowed for the process to be carried out at higher temperatures. However, the coating produced at 20 °C had a larger pore diameter, but numerous defects. The coating obtained from the three-component solution had the most regular structure, but the smallest pore diameter.

Gadolinium-Sensitive Artificial Nanochannel Membrane for Information Encryption.

Inspired from ion channels in the myelinated axon of Xenopus laevis found to be affected by gadolinium on axonal currents, we present a solid nanochannel membrane sensitive to gadolinium (Gd3+), which can be achieved via the use of the macrocyclic triacetic acid derivative in the host-guest chemistry approach. The macrocyclic nanochannel has good responsiveness toward Gd3+, even at the nanomolar concentration level, evidenced by discernible changes in rectification, ionic conductance, and XPS analyses. Notably, the Gd3+-sensitive nanochannel membrane can be switched by the addition of a diethylenetriaminepentaacetic acid (DTPA) derivative. Further studies have indicated that the gated behavior of Gd3+ in the nanochannel can be attributed to the strong binding strength between DO3A and Gd3+, which induces a surface charge reversal within the nanochannel. The mechanism has been confirmed through several experimental techniques, including isothermal titration calorimetry (ITC) experiments, fluorescence titration experiments, and finite element analysis. Based on its Gd3+ responsiveness of the constructed ion channel, we successfully developed an advanced multilevel information encryption application of the artificial solid nanochannel membrane. Furthermore, it is anticipated that a more effective encryption system will be built by utilizing the bionic ion channel system's ease of use and straightforward functionalization.

Analysis of GCRV Pathogenesis and Therapeutic Measures Through Proteomic and Metabolomic Investigations in GCRV-Infected Tissues of Grass Carp (Ctenopharyngodon idella).

Hemorrhagic disease caused by grass carp reovirus (GCRV) infection is a major problem affecting the grass carp aquaculture industry. Therefore, inhibiting the spread of GCRV infection is of great economic significance. Herein, we sequenced five tissues (gill, liver, intestine, kidney, and muscle) from grass carp before and after GCRV infection using data-independent acquisition proteomic and untargeted metabolomic technologies, and quantitatively identified 10,808 proteins and 4040 metabolites. Then, we analyzed the differentially expressed proteins (DEPs) and metabolites (DEMs) before and after GCRV infection in the five tissues. Gene ontology analysis revealed that the five tissue DEPs were enriched in metabolic, including carbohydrate and lipid metabolic processes. Chemical taxonomy analysis showed that the categories of DEMs mainly included carbohydrates and lipids, such as fatty acids, glycerophospholipids, steroids, and their derivatives. Both the proteomic and the metabolomic data showed that GCRV affected the carbohydrate and lipid metabolism in the host. Shared pathway analysis was performed at both the protein and metabolic levels, showing significant enrichment of the glycolysis and pentose phosphate pathways (p < 0.001). Further analysis of glycolysis and pentose phosphate pathway inhibitors revealed that these two pathways are important for GCRV replication. As the kidney was the most affected among the five tissues, we analyzed the butanoate metabolism in the kidney, which revealed that most of the differentially expressed proteins and differently expressed metabolites in the butanoate metabolism were related to the TCA cycle. Further investigation showed that fumaric acid, an intermediate product in the TCA cycle, significantly inhibited GCRV replication in the CIK cells (p < 0.001), and that this inhibitory effect may be related to its induction of interferon system activation. The addition of fumaric acid to feed increased the survival rate of juvenile grass carp by 19.60% during GCRV infection, and protected the tissues of those infected with GCRV, making it a potential anti-GCRV feed additive. Our results provide new perspectives on GCRV pathogenesis and antiviral strategies for grass carp.

Effect of organic acid additives on sulfite oxidation in a calcium-based slurry

The forced oxidation of sulfite ions was conducted to obtain high-quality gypsum in the flue gas desulfurization system. The effects of formic, lactic, acrylic, acetic, propionic, and hexanoic acids added to calcium-based slurry on sulfite oxidation were investigated in this study. Sulfite oxidation was inhibited when the pKa value of organic acids was small or the carbon chain was long. In the identical slurry pH 6, the SO4 2- fractions of slurries with formic and lactic acids, which have the smallest pKa values, were lower than half that of the additive-free slurry. The addition of hexanoic acid with the longest carbon chain showed a similar SO4 2- fraction to that of additive-free slurry. These results indicate that the inhibitory effect on sulfite oxidation is more expressed by the acidity of organic acids. The SO4 2- fraction in the slurry affects the growth and quality of gypsum crystals. The slurry with acetic acid presented the highest SO4 2- fraction and resulted in the formation of high-quality gypsum crystals. The findings of this study can contribute to the selection of organic acid additives with high desulfurization efficiency and the production of high-quality gypsum.

A novel dual-function fluorescence sensor Eu/CDs@MOF-808 for the sensitive detection of adenosine triphosphate and uric acid

Designing and developing a reliable method for the detection of potential biomarker molecules are crucial for the early prevention and diagnosis of diseases. In this study, we present a novel functionalized metal–organic framework material (MOF-808) that is developed to construct ratiometric fluorescence sensing platforms (Eu/CDs@MOF-808) for the detection of adenosine triphosphate (ATP) and uric acid (UA). The fluorescent probe Eu/CDs@MOF-808 prepared through the in-situ encapsulation of fluorescent carbon dots (CDs) within the structure of MOF-808 exhibits excellent optical properties. Additionally, rare earth ions (Eu3+) are incorporated into the CDs@MOF-808 using a post-synthetic modification strategy. The presence of ATP significantly enhances the characteristic peak of carbon dots (CDs) at 440 nm, while the peak of Eu3+ at 614 nm remains relatively unchanged. Furthermore, the concentration of ATP exhibits a strong linear relationship with the ratiometric fluorescence intensity (F440/F614) in the concentration range of 0.5–450 μM, with a detection limit of 0.22 μM. Notably, the addition of uric acid (UA) to this fluorescence sensing platform leads to a marked reduction in the characteristic peak intensity of Eu3+, which results in a satisfactory linear relationship between the ratiometric fluorescence intensity and UA concentration in the concentration ranges of 0.04–300 μM and 300–650 μM, with a detection limit of 0.04 μM. Additionally, the fluorescent sensor has been successfully applied for the detection of ATP and UA in real serum and urine samples.

Three Stages of Nascent Protein Translocation Through the Ribosome Exit Tunnel.

All proteins in living organisms are produced in ribosomes that facilitate the translation of genetic information into a sequence of amino acid residues. During translation, the ribosome undergoes initiation, elongation, termination, and recycling. In fact, peptide bonds are formed only during the elongation phase, which comprises periodic association of transfer RNAs and multiple auxiliary proteins with the ribosome and the addition of an amino acid to the nascent polypeptide one at a time. The protein spends a considerable amount of time attached to the ribosome. Here, we conceptually divide this portion of the protein lifetime into three stages. We define each stage on the basis of the position of the N-terminus of the nascent polypeptide within the ribosome exit tunnel and the context of the catalytic center. We argue that nascent polypeptides experience a variety of forces that determine how they translocate through the tunnel and interact with the tunnel walls. We review current knowledge about nascent polypeptide translocation and identify several white spots in our understanding of the birth of proteins.

The addition of humic acid into soil contaminated with microplastics enhanced the growth of black gram (Vigna mungo L. Hepper) and modified the rhizosphere microbial community.

Microplastics have polluted agricultural soils, posing a substantial risk to crop productivity. Moreover, the presence of microplastic pollution has caused a disturbance in the composition of the microbial community in the soil surrounding plant roots, therefore impacting the growth of beneficial bacteria. A study was conducted to examine if humic acid (HA) can counteract the harmful effects of microplastics (MPs) on the growth of black gram crops and the composition of the rhizosphere soil microbial community, to reduce the negative impacts of microplastics on these microorganisms and crops. The research was carried out using mud pots and the plastic utilized for the experiment consisted of 60% high-density polyethylene (HDPE) and 40% polypropylene (PP). The soil was enriched with lignite-based potassium humate, which had a pH range of 8.0-9.5 and with 65% humic acid. The experiment consisted of six treatments: T1, which served as the control without HA and MP; T2, which involved the use of HA at a concentration of 0.15% w/w; T3, which involved the use of MP at a concentration of 0.2% w/w; T4, which involved the use of MP at a concentration of 0.4% w/w; T5, which involved the combination of HA at a concentration of 0.15% w/w and MP at a concentration of 0.2% w/w; and T6, which involved the combination of HA at a concentration of 0.15% w/w and MP at a concentration of 0.4% w/w. The plant growth characteristics, including germination percentage, nodule number, and chlorophyll content, were measured. In addition, the DNA obtained from the rhizosphere soil was analyzed using metagenomics techniques to investigate the organization of the microbial population. Seedlings in soil polluted with MP exhibited delayed germination compared to seedlings in uncontaminated soil. Following 60days of growth, the soil samples treated with T5 (0.2% MP and 0.15% HA w/w) had the highest population of bacteria and rhizobium, with counts 5.58 ± 0.02 and 4.90 ± 0.02CFUg-1 soil. The plants cultivated in T5 had the most elevated chlorophyll-a concentration (1.340 ± 0.06mgg-1), and chlorophyll-b concentration (0.62 ± 0.02mgg-1) while those cultivated in T3 displayed the lowest concentration of chlorophyll-a (0.59 ± 0.02mgg-1) and chlorophyll-b (0.21 ± 0.04mgg-1). Within the phylum, Proteobacteria had the highest prevalence in all treatments. However, when the soil was polluted with MPs, its relative abundance was reduced by 8.4% compared to the control treatment (T1). Conversely, treatment T5 had a 3.76% rise in relative abundance when compared to treatment T3. The predominant taxa found in soil polluted with MP were Sphingomonas and Bacillus, accounting for 19.3% of the total. Sphingomonas was the predominant genus (21.2%) in soil polluted with MP and supplemented with humic acid. Humic acid can be used as a soil amendment to mitigate the negative effects of MPs and enhance their positive advantages. Research has demonstrated that incorporating humic acid into soil is a viable method for maintaining the long-term integrity of soil's physical, chemical, and biological characteristics.

ОПТИМИЗАЦИЯ СОСТАВА ПИТАТЕЛЬНОЙ СРЕДЫ И УСЛОВИЙ КУЛЬТИВИРОВАНИЯ ДЛЯ МИКРОРАЗМНОЖЕНИЯ IN VITRO THYMUS SERPYLLUM L. И THYMUS CAUCASICUS WILLD.

The study was conducted to optimize the cultivation conditions for the second stage of clonal micropropagation of Thymus caucasicus Willd. and Thymus serpullum L. Stem segments with one node (8…10 mm), obtained by microcutting of shoots, were cultured on 10 different Murashige and Skoog (MS) nutrient media containing 2% sucrose and 0.8% agar-agar, with the addition of kinetin, thidiazuron, benzylaminopurine (BAP), indoleacetic and gibberellic acids. Various culture vessels (jars, flasks, test tubes) were used for micropropagation. The duration of the cultivation cycle varied from 40 to 70 days. The highest reproduction coefficient of T. serpyllum was noted on the MS medium containing 1.0 mg/l BAP and was 6.7, while that of T. caucasicus was on the MS medium containing 1.0 mg/l kinetin (16.1). The highest efficiency of culturing both thyme species was achieved in jars, with the use of which the reproduction coefficient was 1.4…2.1 times higher than when grown in test tubes or flasks. It is advisable to cultivate the studied thyme species with a standard cycle of 40 days. The best combinations of various thyme reproduction factors contributed to the maximum manifestation of the morphogenetic potential in in vitro experiments. The greatest influence on the multiplication coefficient was exerted by the type of culture vessel, the interaction of the composition of the nutrient medium and the genotype, as well as the composition of the nutrient medium (the shares of the influence of factors ranged from 20.0% to 25.3%). The results of the studies served as the basis for the development of a protocol that can be used for accelerated micropropagation of T. caucasicus and T. serpullum.