The authors who are published in this journal agree to the following: The authors retain copyright on the work and provide the journal with the right of first publication of the work on condition of license Creative Commons Attribution-NonCommercial. 4.0 International (CC BY-NC 4.0). The authors retain the right to enter into certain contractual agreements relating to the non-exclusive distribution of the published version of the work (e.g. post it on the institutional repository, publication in the book), with the reference to its original publication in this journal. The authors have the right to post their work on the Internet (e.g. on the institutional store or personal website) prior to and during the review process, conducted by the journal, as this may lead to a productive discussion and a large number of references to this work. (See The Effect of Open Access.)
Pear rust in Belarus because of fungus Gymnosporangium sabinae (Dicks.) G. Winter invasion
Pear rust in Belarus was first registered in 2007, and after 12 years the disease acquired the character of epiphytosis. A map of the distribution of pear rust in the republic has been compiled. The symptoms of damage to pear and juniper, spores of the causative agent (fungus Gymnosporangium sabinae (Dicks.) G. Winter) are described and illustrated. It has been shown that aecio- and teliospores overwintered in the shoots do not germinate in the next growing season. The teliospores of the current year on juniper germinate not only with phragmobasidia with basidiospores, but also with mycelium, which probably ensures the re-infection of this host plant. The high infectious potential of both pear (up to 15 mln aeciospores per 1 cm2 ) and juniper (2 mln teliospores per 1 cm2 ) was determined. The death due to rust of annual shoots of pear and individual plants of the Cossack juniper was ascertained. The invasion of G. sabinae on the territory of Belarus coincides with the wide introduction of susceptible species of juniper into landscaping.
Gymnosporangium sabinae (Dicks.) G. Winter
Copyright (c) 2022 Experimental Biology and Biotechnology
Influence of light intensity and its spectral composition on photosynthetic activity of cucumber Cucumis sativus under fusarium wilt
The responses of cucumber chloroplasts of the Kustovoi variety formed under lighting of different intensity (6000 and 11 000 lx) or under LED lighting with a predominance of red light and far red light to infection with fungus Fusarium oxysporum were studied. The amount of chlorophylls and carotenoids in chloroplasts formed at low light increased in 72 h after infection, and at high light a significant increase in pigment catabolism was observed. Under fusarium wilt, the violaxanthin cycle was not involved in the conditions of the studied light range, and the photochemical activity of chloroplasts did not depend much on the level of illumination. The predominance of red light or far red light caused an increase in both chlorophylls and carotenoids content in terms of the dry mass of the leaf compared to their content in plants grown on white light. Infection on white light and red light caused an increase in the total content of chlorophylls and carotenoids, and a decrease in these parameters relative to healthy plants was noted on far red light. Fusarium wilt led to a decrease in photochemical activity and electron transport of photosystem I (by 20 %) in chloroplasts on red light and far red light. A decrease in the functional efficiency of photosystem II was also observed, most likely due to irreversible changes in pigment-protein complexes with two types of LED lighting. Various mechanisms of the response of cucumber chloroplasts to pathogen infection are discussed, depending on the light conditions of the formation of photosynthetic membranes.
Photosynthetic apparatus of barley plants treated with 5-aminolevulinic acid: mechanisms of adaptation to drought
A significant effect of soil drought on the morphometric parameters of the leaves of barley plants of the Brovar and Avans varieties, the accumulation of reactive oxygen species, as well as the content of photosynthetic pigments in them has been established. It has been shown that during drought, the treatment of leaves of barley plants of the Brovar variety with 5-aminolevulinic acid causes a decrease in the content of proteins of photosystem antenna complexes, which leads to a decrease in the size of the light-harvesting antenna and is an effective mechanism for protecting the photosynthetic apparatus from oxidative stress. Fine adjustment of the photosynthetic apparatus components of leaves of barley plants of the Brovar variety to drought may be a key factor in determining the resistance of this variety to this type of abiotic stress. In the Avans variety, these adaptation mechanisms are either absent or manifest to a lesser extent, which leads to a more intensive development of oxidative stress in plants of this variety under the action of soil drought.
Hemolymph osmolality in mollusk Lymnaea stagnalis during acute experimental hyperglycemia
It has been established that the development of hyperglycemia, accompanied by a multiple increase in the hemolymph glucose content (up to 4.0 – 4.5 mmol/L), doesn’t lead to any significant changes in Lymnaea’ s hemolymph osmolality. Incubation of mollusks in 100 mmol/L aqueous solution of polyethylene glycol 200 for 2 h causes a 1.4-fold increase in hemolymph osmolality (up to 210 mosmol/kg) compared to the control level.
The use of SCoT markers for evaluation of the genetic variability of Russian fescue and festulolium varieties
Forage gramineous grasses are the most important component of the hay lands and pasture agroecosystems. To increase the efficiency of grass breeding the complex evaluation of the initial plant material is necessary, including an application of the current DNA technologies. The aim of this study was to investigate the effectiveness of SCoT markers for PCR-analysis of interspecies and intervarietal genetic variations of Russian fescue (Festuca) and festulolium (× Festulolium F. Aschers. et Graebn.) varieties. Total 13 samples, combined 30 seedlings per variety were genotyped with 25 SCoT markers, indicated as informative for gramineous grasses according to literature sources. The high efficiency of SCoT marking technique as a tool for DNA polymorphism revealing was found for Russian fescue and festulolium species and varieties. The obtained results can be used at the varieties identification and genetic certification as well as for selection the parental forms for the breeding process.
Identification of pectolytic bacterial species isolated during plant bacteriosis in the Republic of Belarus
During 2019 –2020, we selected 75 samples of potatoes, carrots, turnips, cabbage, onions, both in the field and from storage. Bacteria of the genus Pectobacterium were isolated from 60 samples. Strains of Bacillus pumilus, Bacillus sp. and Pseudomonas sp. were also isolated. The dominant species causing soft rot and black leg of potato were Pectobacterium carotovorum, P. parmentieri, P. atrosepticum and P. brasiliense. Bacterium P. carotovorum was isolated from other vegetable crops. In samples of carrots and potatoes, strains of bacteria of the genus Bacillus were often isolated from storage. For the first time in Belarus, we found the bacterium P. brasiliense on potato plants. The results obtained on the identification and spread of soft rot bacteria in Belarus will help plan the risks associated with infections caused by these pathogens.
Electrophysiological and radioisotope analysis of ion fluxes induced by salt and oxidative stress in higher plant root cells
Environmental stresses induce the release of electrolytes from root cells into the extracellular space, including key inorganic and organic ions. This phenomenon is described for salinity, drought, attack of pathogens, exposure to heavy metals, oxidative stress, etc. The efflux of electrolytes is also observed during some processes of normal physiology, being part of the gravitropic response, the formation of polarity and the growth of the cell elongation. Despite the long study of this phenomenon, today its molecular mechanism remains unclear. In the present study, a combined approach based on the labeled atom method (loading isotope 86Rb+ followed by recording the parameters of its efflux from root cells), reverse genetics and the patch-clamp technique has been developed for testing the biophysical and molecular nature of the efflux of electrolytes from the root cells. It has been demonstrated that in the roots of Arabidоpsis thaliana (L.) Heynh., the K+ efflux during salinisation and oxidative stress is catalysed by K+ channels encoded by the GORK gene (guard cell outward-rectifying K+ channel), and the efflux of organic anions – by anion channels encoded by the ALMT1 gene (aluminum-activated malate transporter 1). The characteristics of the combined functioning of these systems under stress have been established.
Immunobiological characteristics of microglial cells and in vitro models for their obtaining
Microglial cells are one of the main cellular elements of the central nervous system. In recent years, more and more data has appeared about the role of microglial cells in the pathogenesis of various mental and neurodegenerative diseases. However, the study of human brain microglia is limited for technical and ethical reasons, so the development of a new in vitro cell model of human microglia is a perspective trend in biology and medicine. The aim of this review is to describe the functional and immunological properties of microglia and to analyse in vitro models that currently used for study the properties of cells in normal and pathological conditions.
Superweak biophoton emission: possible biological significance and ways of practical use
Widespread in nature ability of biological objects to emit photons (biophotons) made it possible to create devices for non-invasive and continuous monitoring of the metabolism of organs and tissues, used as a powerful clinical diagnostic tool, as well as for visualisation and spatio-temporal analysis of functioning organs and, in particular, the brain. Numerous experimental data indicating the participation of biophotons in the processes of inter- and intracellular communication served as a theoretical basis for the medical use of low-intensity light therapy for the effective treatment of a wide range of diseases, including delayed wound healing, pain in arthritis, and acute stroke.
Electrical properties of the sensory neuron and defense reactions of mollusc Lymnaea stagnalis at conditions of prolonged hyperglycemia
Hemolymph glucose level rise (from 0.12 (0.05; 0.18) to 4.10 (3.18; 6.08) mmol/L) modify the defensive behaviour of molluscs. This results in increase of the degree of animal’s body retracted into the shell and in reinforcement of weak defense reactions in response to tentacles’ tactile stimulation. No fluctuations in the tentacles length and the duration of the latent period of protraction were found. At experimental hyperglycemia (incubation of the isolated CNS preparation in 10 mmol/L D-glucose solution for 2 h), the basic electrical characteristics of FMRFamide-containing neuron RPaD1, involved in sensory stimuli detection and heart beat regulation in Lymnaea, were changed. Membrane depolarisation, accompanied by firing rate increase were observed, while current-voltage curve characteristics, as well as membrane resistance, capacity and time constant remains unchanged in comparison with control. An increase in rising and falling phases duration, undershoot amplitude were noted, while other parameters of the RPaD1 spike remained unchanged. Based on the revealed features of the action potential shape at hyperglycemia, it is assumed that these changes can be caused by the activation of the Na+-glucose co-transporter and ATP-sensitive K+-channels of the RPaD1 membrane. The action of glucose should be considered as a metabolic signal also in relation to non-feeding neurons in the mollusc brain.
Crepis rhoeadifolia M. Bieb. (Compositae) in the flora of Belarus
In 2021, the third location of Crepis rhoeadifolia M. Bieb. was identified in Belarus for the last 120 years. The article gives a phytocenotic characteristic of the habitat of C. rhoeadifolia in the Vetkovsky District of the Gomel Region, special attention is paid to the geographical distribution of the species. A map of the general range of C. rhoeadifolia has been compiled, which reflects the current distribution of the species. With the help of the MaxEnt program, the ecological and climatic niche of C. rhoeadifolia was identified, which allows us to come to the conclusion about the adventitious origin and the prospect of further distribution of the species in Belarus.
Organ- and tissuespecific variation in antiradical potential and phenolic compounds content in plants of the genus Taxus spp.
The paper presents the results of an investigation of the antiradical activity, total phenolic and flavonoid contents in aboveground and underground organs and tissues of Taxus spp. plants (T. baccata L. cv. Semperaurea, T. cuspidata Sieb. et Zucc. and T. wallichiana Zucc.) introduced in the Republic of Belarus. The analysis indicates the dependence of antiradical activity value and the level of phenolic compounds on the organ- and tissue-specific localisation. Root periderm (secondary dermal tissue) extracts of all Taxus spp. species studied showed the best antiradical activity with the highest total phenolic and flavonoid contents. Thus, the extracts from the root periderm of T. wallichiana Zucc., T. cuspidata Sieb. et Zucc. and T. baccata L. cv. Semperaurea had antiradical activity of (28.7 ± 1.0), (26.1 ± 0.8) and (22.4 ± 0.7) mg ascorbic acid equivalent per 1 g dry weight, respectively, which was 78–81 % higher than the antioxidant activity of the trunk-bark extracts and 42– 64 % higher than the activity of the needle extracts. The total phenolic content of the root periderm extracts of all investigated plants varied from (129.9 ± 2.9) to (154.2 ± 4.3) mg gallic acid equivalent per 1 g dry weight, and was found to be highest in the T. wallichiana Zucc. extract. The greatest flavonoid content was observed with extracts of the root periderm of T. cuspidata Sieb. et Zucc. ((13.0 ± 0.4) mg quercetin equivalent per 1 g dry weight).
Research of polymorphism of microsatellite markers of Scots pine for the purposes of forensic DNA analysis
Microsatellites as highly polymorphic markers are a valuable tool in identification and population studies. In order to form approaches to forensic DNA identification in the investigation of illegal logging cases, 17 SSR markers of Scots pine (Pinus sylvestris L.) were tested using DNA from plants growing in the western and eastern parts of the Republic of Belarus. High information content was shown for six microsatellite markers. The potential possibility of using a complex of selected markers for the purpose of DNA identification of Scots pine wood samples in forensic examination has been established.
Features fruit set higbush blueberry depending on the cultivar specifications and weather and climatic conditions
On the basis of four-year data, the features of fruit set are shown for 15 cultivars of highbush blueberry. The average yield of ripe berries from the number of flowers varies within a fairly wide range and averages from 46 % (Chandler) to 83 % (Sunrise) for highbush blueberry cultivars. The degree of variability in berry setting indices in the taxa under study varied significantly over the years: from a low level (Bluejay, Nui, Puru, Spartan, Sunrise) to a very high level (Bonus). It was revealed that the lower the level of variability of the fruit setting indicator, the higher the adaptive ability of the taxon to changing weather and climatic conditions. The setting of highbush blueberry fruits is influenced by such weather and climatic factors as humidity and air temperature. Precipitations falling within the range close to the mean annual values or slightly higher than them, and the air temperature close to the climatic norm, contribute to better fruit setting. A pronounced shortage of precipitation, especially against the background of an increased average daily temperature, during flowering and growth of fruits, as well as heavy precipitation during the period of mass flowering of blueberries, have a negative effect on berry setting. At the same time, the main limiting temperature factor during flowering and formation of blueberry fruits is a decrease in air temperature to minus indicators (freesing).
Study of the efficiency of suppressing fire blight by bacteriophages under laboratory conditions
Erwinia amylovora bacteriophages Hena2, Roscha1, Pixel, Dichka and VyarbaS were studied as a biological fire blight control agents on model objects – pear flowers and leaves. When treated with a bacteriophage 1 h before inoculation with E. amylovora 1/79Sm, no statistically significant differences in symptoms were found compared to the control. However, a decrease in the titer of the pathogen by 1–3 orders of magnitude was shown with E. amylovora in the inoculum of 106 –108 CFU/mL and treatment with a bacteriophage 1 h before infection with the pathogen.
The influence of nickel(II) ions in soil on total antioxidant activity and components of the ascorbat-glutathione cycle in transgenic plants Nicotiana tabacum
We conducted a comparative analysis of some biochemical parameters in non-transgenic and transgenic plants Nicotiana tabacum, cultivated in soil with an increased concentration of nickel(II) ions. Transgenic plants had in their genome a bacterial acdS-gene encoding the 1-aminocyclopropane-1-carboxylate deaminase (ACC-deaminase) enzyme. The introduction of elevated concentrations of nickel ions into the soil promotes induction of the acdS-gene expression and an increase in ACC-deaminase activity in transgenic plants. It was shown that the total antioxidant activity and the content of ascorbic acid, glutathione, ascorbate peroxidase, glutathione peroxidase and glutathione reductase increased in plants under abiotic stress.
Cellular catalase: structure, biogenesis, diversity, functions
Catalase is an important antioxidant enzyme that destroys hydrogen peroxide formed in a result of normal cell metabolism, with the formation of water and oxygen, preventing lipid peroxidation of membranes and cell damage. This review analyses and summarises information about the history of discovery, structure, biogenesis, polymorphism and biological functions of cellular catalase.
Gas chromatography – mass spectrometry analysis of acetone extract of Lactuca tatarica (L.) C. A. Mey. roots
Research work is devoted to the chemical investigation of the roots of the Lactuca tatarica (L.) C. A. Mey. by gas chromatography – mass spectrometry method. From the crude extract that is obtained from the roots, the presence of natural compounds of various groups has been detected. As a result, 25 different substances including acyclic compounds (methyl myristate, palmitic acid methyl ester, ethyl palmitate, methyl elaidate, methyl stearate, ethyl oleate, etc.) have been identified from the solid mass of the research object. The most abundant fatty acid esters are methyl oleate (6.831 %) and palmitic acid methyl ester (2.902 %). In addition, the triterpenoid compounds (lupeol acetate, cycloartenol acetate, 3β,13β,14β-13, 27-cycloursan-3-ol acetate) which are characteristic of the L. tatarica have been identified. Lupeol acetate is the predominant component which makes up 56.35 % of the whole obtained substances. Elaidic acid which belongs to the fatty acids group, bis(2-ethylhexyl)phthalate which belongs to the aromatic dicarboxylic acid esters and other compounds have also been identified. Among the identified substances, some are found previously from the other species of the genus Lactuca L. but with regards to the L. tatarica to the best of our knowledge the majority of them are firstly being reported in this study. The investigated plant is widespread in the lowlands and coastal areas of Azerbaijani flora. The availability of some pharmacological effective compounds (lupeol acetate, 3β,13β,14β-13, 27-cycloursan-3-ol acetate, olean-12-en-3-yl acetate) makes the research significant in terms of chemical aspect. Therefore, the results of this investigation open up new horizons for future studies in various fields including the pharmaceutical one.
Stress-induced electrolyte leakage from root cells of higher plants: background, mechanism and physiological role
Electrolyte leakage from tissues is one of the central reactions of the plant organism to stress. It is observed under almost any type of stresses, both abiotic and biotic. The loss of key electrolytes can lead to significant changes in metabolism and, in some cases, to the death of cells or the whole organism. For a long time, it was believed, that electrolyte leakage is associated with disruption of cell integrity and plasma membranes degradation, and that it is an unregulated process. However, in recent years, a lot of evidence has been received that, in most cases, electrolyte leakage is inhibited by ion channel blockers and reversible. It means that it is associated with the transfer of ions through the membrane by transport proteins, such as ion channels. Recently, the experimental evidence has been obtained, that under salinity, drought, pathogen attack, excessive levels of heavy metals, hypo- and hyperthermia, as well as oxidative stress, the electrolyte leakage in plant cells is mediated by several types of cation and anion channels, including K+-selective channels (SKOR and GORK), anion channels (such as ALMT1) and a number of non-selective cation channels. It has been demonstrated that the primary reactions that induce electrolyte leakage are plasma membrane depolarisation and generation of reactive oxygen species, leading to the activation of redox-regulated outwardly rectifying K+ channels, such as SKOR and GORK. Potassium efflux is up-stream and stimulates the counterion flow (transport of anions) through the anion channels. The regulation of electrolyte leakage at the ion channel level and the corresponding selection for ion channel properties can become an important link in the directed control of stress resistance in higher plants. This can be applied in agriculture via breeding of stress-tolerant plant varieties, as well as developing modern amelioration techniques.
Pollen cargo structure on Aculeata – visitors of alien Solidago canadensis L. s. l. inflorescences in Belarus
Community structure of visitors to inflorescences of invasive goldenrods was investigated by sampling at 9 sites in Minsk city, Minsk and Mogilev regions in Belarus. A total 44 species of Aculeata including 1 species of Chrysioidea, 7 species of Vespoidea and 36 species of Apoidea were registered. Among them 2 species of bumblebees (Bombus terrestris L., B. lapidarius L.) were numerous, 2 species of Vespoidea (Polistes dominula Christ, P. nimpha Christ) and 3 species of Apoidea (Philanthus triangulum F., Hylaeus communis Nyl., B. ruderarius Müller) were common. Pollen cargo analysis revealed the predominance of easily lost and relatively easily lost conspecific pollen grains on the bodies of the imago of the all common and numerous species of visitors to inflorescences of invasive goldenrods.
Accumulation and antigenicity of truncated porcine circovirus type 2 capsid protein in Escherichia coli cells
This work examines accumulation of shortened version of porcine circovirus type 2 capsid protein (SOP protein) in the cells of bacterial strain Escherichia coli BL21-CodonPlus(DE3)-RIPL with plasmid pET-SOP, obtained in previous work. The gene for SOP protein was modified by deletion of the part (108 base pair) interfering expression in procaryotes, as well as optimisation of 93 rare codons. Under cultivation temperature 37 °C for 2 h after induction the proportion of target protein reaches of 24 % of the total cellular protein, which makes it possible to classify this strain as an effective industrial producer of target protein. During the cultivation of the producer at 37 °C, the target protein is in the cells in the native soluble form right after induction, but 1 h after the addition of the inducer, it is found mostly in insoluble multimeric form (inclusion bodies). When the cultivation temperature is lowered to 18–30 °C, the formation of inclusion bodies slows down, however the proportion of recombinant protein in the cells of the producer decreases to 15– 6 % respectively, which significantly reduces the profitability of the technological process. It has been established that the modified recombinant SOP protein obtained from bacterial cells of the producer strain retains its antigenic activity, which is confirmed by specific enzyme-linked immunosorbent assay analysis. These data allow us to consider studied protein as a promising candidate for a porcine circovirus type 2 vaccine.
Dynamics of gut microbiota in patients suffering from hematologic malignancies after allogeneic hematopoietic stem cell transplantation
In this study, we described the dynamics of intestinal microbiota of 32 patients after allogeneic hematopoietic stem cell transplantation (HSCT). After HSCT, on 14th day and 30th day, the inverse Simpson index value was more than 3 times lower compared to the pre-HSCT period. Biodiversity became more similar to the pre-HSCT level by 100th day. The correlation between diversity of microbiota and development of post-HSCT complications wasn’t observed. Our findings indicated individual-specific changes in the taxonomic structure of patients’ microbiota after HSCT. Changes in the relative abundance of the bacterial families Streptococcaceae, Actinomycetaceae, Acidaminococcaceae, Akkermansiaceae, Desulfovibrionaceae, Prevotellaceae, genera Streptococcus, Clostridioides, Phascolarctobacterium, Paraprevotella, Bilophila, Akkermansia, Coprococcus, Sutterella, Alistipes appear to be associated with the development of post-HSCT complications. High abundance of phylum Proteobacteria, families Actinomycetaceae and Streptococcaceae, genus Streptococcus before HSCT can be considered as a potential predictor of graft-versus-host disease development in the post-HSCT period.
Development of a microsatellite panel for identification of biological samples of moose (Alces alces) in forensic research
For forensic analysis of evidence from illegal hunting sites of moose, a panel of 15 microsatellite (4 tetranucleotide and 11 dinucleotide) loci and 1 sex locus (amelogenin) was proposed. The cumulative power of discrimination of individual based on the common genetic database of moose (for a panel of 15 microsatellite loci) is more than 99.999 999999 999 %. The genetic and forensic indicators of a microsatellite panel were evaluated on a population sample of moose on a national scale (383 samples) for the first time in Europe and forensic methodology of the DNA identification of the moose (Alces alces) introduced into the national legal system.
Characteristic of strains Priestia megaterium Ср-1 and Rhodococcus jostii СА-6 demonstrating increased salt resistance
The strains Priestia megaterium Ср-1 and Rhodococcus jostii CA-6 were shown to preserve phosphate-solubilising ability, nitrogen-fixing activity and synthesis of indole-3-acetic acid under osmotic stress conditions caused by sodium chloride in concentration range of 1197–2052 mmol/L, as well as to promote seed germination rate and development of small radish seedlings. Proline, betaine and sucrose were found to exert a beneficial effect on growth and ability of strains P. megaterium Ср-1 and Rh. jostii CA-6 to adapt to osmotic stress. Mass spectrometric analysis has revealed that intracellular synthesis of proline and betaine in both bacteria was directly proportional to sodium chloride concentration: rising NaCl level in the medium to 1197 mmol/L was accompanied by increase in proline level from 0.062 to 1.502 µg /mL (Rh. jostii CA-6) and from 0.089 to 2.105 µg /mL (P. megaterium Ср-1), in a similar manner betaine production grew up from 0.071 to 0.118 µg /mL (Rh. jostii СА-6) and from 0.055 to 0.219 µg /mL (P. megaterium Ср-1).
Knockout of the T-cell receptor and HLA class I genes in human cells using the CRISPR /Cas9 system
The CRISPR /Cas9 system has found a wide application in cell biology as a tool for gene knockout. In particular, the CRISPR /Cas9 system is used to create allogeneic CAR-T lymphocytes by knocking out the genes TRAC, TRBC1, TRBC2 and B2M. To obtain a large number of cells of the desired phenotype, it is necessary to optimise the process of genomic editing, the effectiveness of which is determined by the sgRNA used. In this work, we experimentally determined the most effective sequences that allow to obtain up to 60.3 % of cells negative for the expression of the B2M protein and up to 71.8 % of cells negative for the expression of the T-cell receptor. It has also been shown that the simultaneous use of two sgRNAs for gene knockout demonstrates a lower efficiency compared to using these sgRNAs separately.
Analysis of the efficiency factors of electrotransformation of Bacillus subtilis to inactivate the aroK gene by the method of homologous recombination
A hyper-osmotic electrotransformation method was developed for strain Bacillus subtilis. Sorbitol and mannitol are included in the hyper-osmotic electroporation medium and recovery medium. In this study, the hyper-osmotic electroporation method was optimised to increase the transformation efficiency of B. subtilis strain 5434 (non-transformable by chemical methods) by 430 fold, with a maximum value of 8.6 ⋅ 105 CFU/µg of integrative plasmid DNA. With the electroporation setted 25 µF, 23 kV/cm, 200 Ω, the method was optimised as follows: a) the OD600 value of the bacterial culture solution was increased to about 1.2, which significantly enhanced survival of bacteria and quantity of viable B.subtilis strain 5434 cells after electroporation; b) the elution frequency of washing solution (hyper-osmotic electroporation medium) for complement cells was increased from 3 to 5 times, resulted in significantly reducing the conductivity of the hyper-osmotic electoporation medium with competent cells (electrocompetent cultue), and effectively extending the pulse time under the same electric field strength; c) quantity of integrative plasmid DNA added to hyper-osmotic electrocompetent culture was optimised. These results indicate that increasing the number of viable B. subtilis strain 5434 cells and reducing the number of metal ions in the electroporation solution mix (integrative plasmid DNA, competent cells of B. subtilis strain 5434, electroporation medium) are useful approach to improve transfomation efficiency of B. subtilis strain 5434. Concentration of shikimic acid in the fermentation medium was quantified by high performance liquid chromatography. Quantification of shikimic acid revealed that B. subtilis strain 5434p4SA produced 403.98 ± 9.1 µg/mL of shikimic acid.
Copyright (c) 2021 Journal of the Belarusian State University. Biology
Lignin phenols as a basis for biopreparations
The content and composition of lignin phenols in plants and soils of latitudinal zones and vertical natural zones of the North Caucasus and Northwest Tien Shan have been studied. The special role of lignin phenols of underground plant organs in the process of humification was revealed. It was shown that the oxidation degree of the biopolymer increases during the transformation of organic matter from living plant tissues to humic acids in soils. The fraction of lignin fragments that remain unchanged during the biotransformation of the polymer in the row plant tissues – fall – litter – soils – humic acids – buried humic acids is calculated. It has also been demonstrated that the biochemical composition of plants has a decisive effect on the structure of humic acids in soils. With the help of quantitative analysis of lignin phenols and 13C NMR spectroscopy, it is proved that lignin of higher plants is involved in the formation of humic acids, both aliphatic and aromatic parts of molecules. The areas of application of lignin phenols in the practice of agriculture and medicine are proposed.
Increasing the antimicrobial activity of Pseudomonas brassicacearum S-1 by inactivation of lysR3 and mtfA genes
Site-specific markerless inactivation of genes lysR3 and mtfA of bacteria Pseudomonas brassicacearum S-1 was carried out. It was shown that strains P. brassicacearum S-1-lysR3, P. brassicacearum S-1-mtfA and P. brassicacearum S-1-lysR3-mtfA demonstrate increased antagonistic activity against a number of phytopathogens 1.2–1.6 times higher compared with the original strain. In the laboratory experiment, mutant variants did not affect growth and development of tomato, cucumber and parsley plants. Treating tomato and cucumber seeds with a solution of the culture of the strain P. brassicacearum S-1-lysR3-mtfA led to the increase of seedlings roots length by 1.4 times compared with the original strain. We also determined that the examined strains were able to survive in the soil microbial consortium.
The investigation of adaptogenic and hepatoprotective properties of Ilex paraguariensis on experimental models in vivo
This work is devoted to the study of the effect of Ilex paraguariensis decoction for energy and carbohydrate metabolism in conditions of increased physical activity, the analysis of the stabilisation possibilities of liver injury and lipid peroxidation markers in rats in an experimental model of chronic alcohol intoxication. It’s established that I. paraguariensis exhibits antioxidant and hepatoprotective effects in rats with experimental alcoholic liver, comparable to the action of classical plant hepatoprotector – Silybum marianum, has a stimulating and adaptogenic effects in experimental model of physical activity, comparable to the energy drink «Wild Jaguar». The results obtained may be due to the presence of flavonoids, ascorbic and chlorogenic acids, exhibiting an antioxidant effect, as well as caffeine, which is known to stimulate the work of the central nervous and cardiovascular systems.
Microsatellite markers in the study of polymorphism of domestic pig breeds (Sus scrofa domesticus)
Using 13 tetra- and 7 dinucleotide microsatellites, we studied the polymorphism of 6 breeds of pigs - Belarusian large white (BLW), Belarusian meat (BM), Belarusian black motley (BBM), Landrace (LR), Yorkshire (YR) and Duroc (DR), which are bred in Belarus. A high level of genetic polymorphism is shown for all breeds, with the exception of the DR breed. For 6 breeds, a low level of inbreeding is shown. Alleles peculiar only to these breeds were found in the gene pools of all the studied breeds. This fact confirms the importance of preserving local breeds for maintaining polymorphism in domestic pigs as a whole. Estimation of genetic distances reveals a significant contribution of the commercial European breeds of Landrace and Yorkshire, however, the evolutionary paths of all three native breeds differ.