Search and application of effective probiotic microorganisms are of great scientific and practical importance for biotechnology and the food industry. Particular attention is drawn to lactic acid bacteria (LAB) isolated from fermented plant raw materials, as a source of natural isolates with high adaptive potential. Further investigation of their properties opens up prospects for the development of new plant-based functional products with probiotic properties. Aim. To isolate LAB cultures from fermented vegetables and berries and to study their probiotic properties. Methods. LAB were isolated from fermented plant raw materials (cabbage, cucumbers, cherries) by the method of serial dilutions followed by plating on MRS agar medium. Species identification was carried out based on morphological characteristics, physiological and biochemical tests, and carbohydrate fermentation profiles using the ABIS online service. Probiotic properties were evaluated by: (a) resistance to low pH (pH 2.0) and bile (0.5%) in phosphate buffer; (b) antimicrobial activity (agar diffusion method); (c) autoaggregation ability (measuring optical density at 600 nm); (d) enzymatic activity (amylolytic and proteolytic); and (e) antibiotic resistance (disk diffusion method). Statistical analysis of the obtained results was performed using Duncan’s test at a significance level of p < 0.05. Results. A total of 45 LAB cultures with similar colony and cell morphology were isolated from different plant sources. Identification revealed that the isolates belonged to Lacticaseibacillus rhamnosus, Lactiplantibacillus plantarum, and Lacticaseibacillus casei species. All cultures showed resistance to acidic conditions (pH 2.0) and bile salts; however, the most stress-tolerant strain was Lpb. plantarum S2. No proteolytic or amylolytic activities were observed in any of the strains. Antagonistic activity was detected against test cultures of conditionally pathogenic bacteria such as B. subtilis, S. aureus, and E. coli. Antibiotic resistance to aminoglycosides, glycopeptides, and polypeptides was identified, while sensitivity to chloramphenicol, tetracycline, erythromycin, and rifampicin was established. The cultures demonstrated high autoaggregation levels, with the highest observed after 24 hours for Lpb. plantarum S2. Conclusions. Lactic acid bacteria were isolated from fermented cabbage, cucumbers, and cherries. The best results – high resistance to acidic conditions and bile salts, as well as antagonistic and autoaggregation properties – were shown by the isolate Lactiplantibacillus plantarum S2.
Wild herbaceous plants are a valuable natural resource, which are a source of plant food and medicinal raw materials and play an important role in the functioning of natural ecosystems. They produce a variety of biologically active compounds of various orientations. The growth conditions of medicinal plants affect their microbiological purity, the activity of biological compounds that they synthesize, as well as the suitability of these plants for further use. In particular, dry medicinal herbs may contain various microorganisms. The aim of this work was to investigate the composition of the microbiota of these plants and to investigate the properties of lipopolysaccharide (LPS) isolated from one of the strains of Escherichia coli isolated from Hypericum. Methods. For the research, the plants of hypericum (Hypericum perforatum L.), meadow clover (Trifolium pratense L.), plantain (Plantago major L.), dandelion (Taraxacum officinale Wigg.), and wild chicory (Cichorium intybus L.), which are used in official medicine to obtain herbal medicines, were taken. The analysis of plant contamination with microorganisms was carried out by inoculating them on commonly used MPA and selective nutrient media: Scharlau CETRIMIDE AGAR (A), (Solid medium for the isolation of Pseudomonas aeruginosa), Scharlau MacCONKEY AGAR (B), and Scharlau XLD Agar (C) (for the isolation of E. coli). LPS from one of the Escherichia coli strains isolated from hypericum was obtained by the water-phenol method; the monosaccharide and fatty acid composition was identified on an Agilent 6890N/5973 chromatographic-mass spectrometric system, and heterogeneity was determined by SDS-PAAG electrophoresis. Results. As a result of analysis of the microbiota that grew on selective nutrient media after inoculation of plant material on them, 35 isolates of microorganisms, representatives of Pseudomonas aeruginosa and Escherichia coli, were isolated. They were isolated from plant material, regardless of where the plants were collected -- near the Zhuliany airfield, Nizhyn, or from the pharmacy network. In the LPS of E. coli 43, isolated from hypericum, which grew near the Zhuliany airfield, the dominant monosaccharides were galactose (36.64%), mannose (30.62%), and glucose (24.13%). Only three fatty acids, 3-hydroxytetradecanoic (44.8%), tetradecanoic (32.6%), and dodecanoic (22.6%), were identified in its composition. The studied LPS turned out to be toxic, like the LPS of previously studied representatives of E. coli, but apyrogenic. This distinguishes it from the LPS of other E. coli representatives, which exhibit high pyrogenicity. It can be assumed that this is due to the fact that it is isolated from plants, in particular, hypericum. LPS is heterogeneous, which is manifested in its formation of a classic profile in the form of a ladder on electrophoresis. Conclusions. Medicinal herbs collected from different ecological niches: the pharmacy network, near the Zhulyany or Nizhyn airfields, are contaminated to varying degrees with representatives of P. aeruginosa and E. coli. E. coli LPS isolated from hypericum differed in biochemical characteristics and biological activity from LPS isolated from other sources. Most likely, these differences are due to the peculiarities of each strain studied.
Despite the significant socio-economic consequences of viral diseases, the issue of the quantity and quality of antiviral drugs remains unresolved. Viruses can mutate and become susceptible to treatment. Therefore, the search for various new strategies to combat viral infections remains relevant. Some TiO2&Ag bioactive nanocomposites (NCs) with a specific surface area of 30.65–50.84 m2/g, a point of zero charge (PZC) of nanoparticles of pH 6.2–9.4, depending on the silver content, were chemically synthesized. The purpose of the work was to study the biocompatible, structural-morphometric, toxicological, and virucidal properties of NCs. Methods. NCs based on titanium oxide (IV) with 4% and 8% silver were obtained by modification of TiO2. The structural, surface, toxicological, and hygienic characteristics of TiO2, TiO2&Ag (4 mass% Ag), and TiO2&Ag (8 mass% Ag) nanopowders were studied. For the toxicological and hygienic assessment, the following methods were used: general toxicity, inductively coupled plasma optical emission spectroscopy, immunological methods, and evaluation of the functional state of boar sperm. The preparation of mouse kidney samples for morphological examination was carried out by standard methods with staining using Sirius Red and Weigert's hematoxylin. The cytotoxic effect of substances was studied using the MTT assay. Virucidal activity was determined against human adenovirus serotype 2 (HAdV-2), herpes simplex virus type 1 (HSV-1, strain US), influenza virus type A, (H1N1) strain A/FM/1/4; the contact time with NC was 60 min. Results. The modification of titanium dioxide nanoparticles with silver leads to a significant increase in the adsorption, catalytic, and chemical activity of the surface of TiO₂&Ag, which ultimately results in enhanced biological activity. This leads to a significant increase in the general toxic effects of TiO₂&Ag compared to nano-TiO₂, greater accumulation of titanium in the liver of mice, manifestation of immunotoxic effects, and inhibitory action on boar sperm. Compared to nano-TiO₂, nano-TiO₂&Ag causes more pronounced initial morphological changes in the organ responsible for excreting metal nanoparticles—the kidneys and more effectively crosses the blood-brain barrier. The toxic effect of NCs in the cell lines and the virucidal effect against model RNA and DNA virusesinfluenza A virus (N1H1), human adenovirus (HAdV-2), herpes simplex virus type 1 (HSV-1) were investigated. The greatest toxicity of NCs was shown in human laryngeal carcinoma Hep-2 tumor cells and Syrian hamster kidneys. A significant virucidal effect of NCs was revealed against all viruses within 60 min of contact, viruses were completely inactivated; and the titer of influenza virus decreased by 10 lg, adenovirus – by 7.4 lg, and herpes simplex virus – by 5 lg. Conclusions. The created nanocomposites can be used to inactivate RNA- and DNA-containing viruses outside the cell (by disinfection of surfaces, liquids, and air) in line with the reduction of their toxic properties.
The aim of the work was to study the state of polymorphonuclear leukocytes (PMN) in patients with acute infected necrotizing pancreatitis (AINP) depending on the type of pathogen. Methods. In patients with AINP in the preoperative period and in patients of the control group, the metabolic activity of blood neutrophils in the SP and ST test with nitroblue tetrazolium (NBT), as well as the PR of metabolic activity were determined in the blood. The percentage of active PMN in the phagocytosis reaction (a percentage of neutrophils involved in phagocytosis) and the number of absorbed Candida albicans particles on average by one PMN - PhI were studied. Results. Pseudomonas aeruginosa, Escherichia coli, Enterococcus faecalis, Klebsiella pneumoniae, Acinetobacter baumannii, and Staphylococcus epidermidis were the most common bacterial pathogens identified in AINP patients. The patients with G(-) microorganisms had a significantly increased number of formazan-positive blood PMN in the ST NBT test, as well as PhN of blood PMN compared to patients with G(+) microorganisms. The metabolic activity and phagocytic index of blood PMN in patients with infected APN did not differ depending on the monoculture or association with isolated microorganisms. However, patients with a monoculture of microorganisms had a significantly increased PMN blood phagocytic index compared to patients with microbial associations. Conclusions. In patients with acute necrotizing pancreatitis, there are disturbances in the functional activity of the PMN. The main directions of the disorders are a significant activation of the processes of blood PMN metabolism. A significantly increased PhN of blood PMN was found in patients with G(-) microorganisms compared to patients with G(+) microorganisms. It was found that patients with microorganisms monoculture had a significantly increased PhN of blood PMN compared to patients with microbial associations.
Seasonal influenza viruses are pathogens that pose a constant threat to human health. They circulate everywhere and cause seasonal rises in the incidence of varying degrees of intensity in the Northern and Southern Hemispheres. These viruses are characterized by variability both due to antigenic drift and connection with the ability to reassort genes. It is known that certain amino acid substitutions in the hemagglutinin (HA) of the virus contributed to its transition to the use of human cellular receptors, which caused pandemics. The aim of the work was to analyze the literature data on the possible impact of mutations in HA and neuraminidase (NA) of seasonal influenza viruses (A(H1N1)pdm09, A(H3N2), B/Victoria)) on their properties, epidemic potential, and degree of clinical manifestation of the disease. The B/Yamagata influenza virus has not been analyzed because its circulation has effectively stopped amid the COVID-19 pandemic. It has been shown that influenza viruses A(H1N1)pdm09, A(H3N2), and B/Victoria differ significantly in terms of evolution. In dynamics, it was demonstrated the amino acid substitutions that occurred in the HA and NA of influenza viruses, including those that affected antigenic properties, resistance of viruses to specific drugs, and clinical symptoms of influenza. Those mutations that contribute to the increase in the reproduction of viruses in cell cultures and chicken embryos and affect certain biological properties of the virus are also considered. Data on the comparison of mutations in influenza viruses of different clades and viruses circulating in different geographical areas are presented. It is shown that under virtually the same initial conditions, the A(H3N2) virus among other influenza viruses showed significantly higher epidemic activity against the background of the pandemic. In the future, as was observed before, the intensity of its circulation will decrease, and the prevalence of other influenza viruses will increase, to which a layer of susceptible population will accumulate over the time. During the pandemic, the circulation of B/Victoria viruses was significantly lower than that of A viruses, especially during the first pandemic seasons. B/Victoria viruses are characterized by less pronounced HA variability than influenza A viruses. The higher antigenic stability of the virus contributes to the longer circulation of certain genetic variants of the virus with a relatively stable level of intensity and the longer use of the same vaccine variants of the viruses. Despite the large amount of data on monitoring the evolution of seasonal influenza viruses and studying the impact of amino acid mutations in HA and NA on the biological properties of the virus, their epidemic potential, and virulence potential, there are still many issues that need to be studied.
The Fusarium solani (Mart.) Sacc. species complex (FSSC) dominates among phytopathogenic fungi in soil mycobiota and negatively affects seed germination in Ukrainian soils. Soybean is quite sensitive to the pathogenic effect of these fungi. F. solani infects seeds and seedlings in the soil and causes their non-germination, deformation, and root rot and necrosis of plants. This study aimed to develop an express analysis to determine soybean resistance during seed germination and to identify strategies to limit the spread of FSSC. Methods. The number of soil fungi was determined by the dilution method. F. solani was identified by cultural and morphological characteristics. The effectiveness of seed treatments was evaluated using an infection index and calculated via a standardized formula. Results. An express assay was developed to detect FSSC-resistant soybean genotypes. Out of the nine tested varieties, Niagara was identified as highly resistant. Testing Niagara across different soil samples showed infection rates ranging from 0% to 21.7%, with the lowest pathogen levels found in chornozems from the northeastern region. Two seed treatment schemes for Niagara were evaluated: 1 – Averkom®, a. s., Sporazin, a. s., and Ecovital, a. s.; 2 – Merivon® Pro, CS, Vitazyme, a. s., and Ecovital, a. s. These treatments increased seed germination and reduced seed damage by F. solani. Their efficiency was 71.8 and 85.5%, respectively. It was determined that isolates of F. solani from soybean are capable of infecting seeds of the following crops through the soil: peas, beans, and sunflowers. Conclusions. The developed express analysis is effective for detecting resistant genotypes to seed infection during the germination period to F. solani. The tested seed treatment schemes of resistant varieties are highly effective.
The phytosphere microbiome plays a key role in maintaining plant health under stressful environmental conditions. Endophytic microorganisms are particularly important due to their different probiotic functions. The aim of the work was to study the effect of endophytic bacteria on phytopathogenic microorganisms, soybean resistance to biotic stresses and its productivity. Methods. Microbiological (cultivation of microorganisms to obtain microbial bioformulations, study of the germination of phytopathogenic micromycetes spores by light microscopy, study of the antagonistic activity of endophytes against phytopathogenic bacteria by the agar block method), biochemical (determination of siderophore synthesizing activity), laboratory-vegetation (research of the effect of endophytes on soybean resistance to phytopathogens under artificial infection), field (soybean plant cultivation, determination of their resistance to diseases under natural infectious background and productivity), and statistical (the significance of the differences determination). The following microorganisms were studied in the work: endophytic bacteria, soybean nodule bacteria, phytopathogenic bacteria, and fungi. Results. Endophytic bacteria isolated from soybean nodules showed antagonism to pathogens of legume and vegetable crops (growth retardation zone diameter from 13.4 to 20 mm) and inhibited the germination of the phytopathogenic fungi spores Fusarium oxysporum 080721 and Alternaria alternata 150721. The ability to synthesize siderophores was detected in all strains, among them Paenibacillus sp. 1, Bacillus velezensis IMV B-8134, and Pseudomonas sp. 6 were the most active, with 75.9%, 57.7%, and 78.3%, respectively. Under soybean seeds inoculation with RyzobinK + B. velezensis IMV B-8134, followed by spraying the leaves with the metabolites of this strain, the protective effect was observed against F. oxysporum 080721 (70.1%), A. alternata 150721 (50.9%), and P. savastanoi pv. glycinea UCM B-1150 (61.9%). Under field experiments on a natural infectious background, inoculation of soybean seeds of different varieties with the composition of RyzobinK together with endophytic strains resulted in protection against alternariosis ranging from 47.5 to 92%. Soybean productivity was also increased. Conclusions. Selected strains of endophytic bacteria are promising for the development of multifunctional microbial preparations for new adaptive biotechnologies capable for maintaining plant health and helping to prevent crop losses under biotic stresses. The use of endophytic bacteria in soybean cultivation technologies will increase plant resistance to pathogens and yield under adverse phytosanitary environmental conditions.
Wheat streak mosaic virus (WSMV) is the most harmful virus of cereals and is an economically important virus in wheat grown in many countries, including Ukraine. The most effective plant defense against viruses is effector-triggered immunity (ETI) provided by R proteins encoded by R genes. The R gene, which is named Wsm1, provides broad wheat resistance against WSMV compared to the other three known today resistance genes. The goal of this study was to screen wheat varieties grown in Ukraine for the presence of resistance gene Wsm1 using a PCR-based marker. Methods. Visual diagnosis, DAS-ELISA, total RNA extraction, and RT-PCR were used for the WSMV identification in wheat samples. Extraction of plant genomic DNA and PCR with primers for the detection of the Wsm1 gene were carried out. Bioassay and ELISA were used for checking the effectiveness of Wsm1-based resistance. Results. For the first time in Ukraine, screening of 102 wheat varieties/breeding lines for the presence of the Wsm1 gene was performed using a PCR-based marker. Our study demonstrates that the Wsm1 gene is present in the 12 investigated wheat varieties/breeding lines that are widely used in Ukrainian farms. Bioassay results confirmed by DAS-ELISA show effectiveness of the resistance gene Wsm1 against WSMV inoculation in experimental conditions. Conclusions. Investigated wheat varieties carrying the Wsm1 gene can be provided to the breeding programs in Ukraine. To our knowledge, this is the first report about screening different wheat varieties grown in Ukraine for the presence of the Wsm1 gene.
The study of field isolates of Yersinia bercovieri is of particular relevance due to the growing global problem of antibiotic resistance and the need for a deeper understanding of the pathogenic properties of the Yersinia genus. These studies can greatly contribute to the development of new approaches to the diagnosis, prevention, and treatment of infections caused by this pathogen, as well as to the improvement of biosafety monitoring strategies in the agricultural sector. In this study, the aim was to comprehensively investigate the biological, phenotypic, and molecular genetic properties of a Y. bercovieri isolate isolated from beet surface washings in 2024. Methods. An integrated approach that combined classical methods of bacteriological analysis with modern molecular genetic techniques allowed us to obtain reliable data on the species affiliation, adaptive properties, and potential pathogenicity of the isolate. Results. It was found that the isolated microorganism formed colonies typical for the genus Yersinia on selective nutrient media, showed temperature dependence of motility (mobile at 23 °C, immobile at 37 °C), demonstrated enzymatic activity characteristic of Y. bercovieri, and formed a dense biofilm at 23 °C. Experiments on laboratory animals (white mice) confirmed the pathogenicity of the isolate, which is important for assessing the potential risk to human and animal health. Of particular concern was the detection of multidrug resistance of the isolate to a wide range of antimicrobial agents, which makes it a valuable object for testing the effectiveness of new antimicrobial agents and disinfectants. Species identification of the isolate was confirmed by sequencing of the 16S rRNA gene, the results of which were registered in the international GenBank database (NCBI) under the number PQ308372. Conclusions. The data obtained are of high practical value and allow us to recommend Y. bercovieri strain 1/2024 as a standard strain in bacteriological laboratories to ensure the accuracy of yersinia diagnosis, quality control of growth media, differential diagnostic tests, differentiation of field isolates, as well as testing of new therapeutic agents and antimicrobial technologies.
Antibiotics are used for therapeutic and prophylactic purposes in both medicine and veterinary medicine, as well as growth stimulants on farms and in aquaculture. Pollution of natural waters with antibiotics has an extremely negative impact on the environment, aquatic biosystems, and human health, leading to the formation of antibiotic-resistant bacteria and antibiotic-resistant genes. The availability of antibiotics in water resources and the methods for their degradation are extremely urgent problems for Ukraine. They have significant potential for the development of aquaculture in the domestic market and may become important exporters of fish products in Europe in the future. Military aggression and the blowing up of the Kakhovka Hydroelectric Power Plant exacerbated the problems with the pollution of water bodies in Ukraine, including antibiotics. Removal of antibiotics is an important problem in wastewater treatment and the preparation of drinking water for use. One of the promising methods for the destruction of antibiotics and other xenobiotics is biodegradation, in particular decomposition using activated sludge, microbial strains, degradation of antibiotics by electroactive biofilm, and enzymatic degradation of antibiotics. Aim of the work. To analyze and summarize information on antibiotic contamination of water systems and the use of microbial biotechnologies for the degradation of antibiotics in aquaculture and natural water bodies. Results. The presented work examines the most relevant methods of antibiotic degradation in aquatic ecosystems with the involvement of microbial biotechnologies.
In streptomycetes, the clusters of genes that determine biosynthesis in the vast majority of antibiotics are usually located on chromosomes, but some of them are located on large plasmids. Some of them are silent and do not express. The development of a number of modern scientific technologies of molecular biology and bioinformatics makes it possible to identify silent clusters in the genomes of streptomycetes. The aim of the work was to identify streptomycetes, the genomes of which contained sequences similar to the cluster of genes of S. coelicolor A3(2), which determine the synthesis of methylenomycin antibiotic (mmy/mmf-cluster). Methods. The objects of the study were nucleotide sequences of chromosomes and plasmids of streptomycetes, which were deposited on publicly available Internet databases on the National Center for Biotechnology Information. The analysis of primary DNA structures was performed using Basic Local Alignment Search Tool. The sequence of mmy/mmf-cluster (SCP1 plasmid of S. coelicolor A3 (2)) was used as a request in a computerized analysis of nucleotide sequences. Results. Sequences similar to the mmy/mmf-cluster and its individual genes were found in plenty of streptomycete genomes belonging to different species. However, the complete sequences of probable clusters were found only in a few streptomycete genomes. Of these, two sequences are localized on plasmids (NZ_CP109276.1, NZ_CP109103.1). Based on the similarity of the 16S rRNA gene sequences of the Streptomyces strains of interest and the corresponding gene of S. coelicolor A3(2), the genetic relatedness of most of the analyzed Streptomyces strains to S. coelicolor A3(2) was determined. Methylenomycin resistance genes (mmr and mmyJ) have been found in the genomes of many streptomycetes that did not contain mmy/mmf-clusters, including two plasmids. Conclusions. The probable mmy/mmf clusters are present in genomes of streptomycetes with different genetic affinity of S. coelicolor A3 (2). Of these, strains Streptomyces sp. NPDC052727, Streptomyces sp. NPDC052721, Streptomyces sp. NRRL S-31 are not genetically related to S. coelicolor A3(2). Two plasmids (NZ_CP109276.1, NZ_CP109103.1) have been identified, in which mmy/mmf-clusters are present.
Microorganisms in combination with metabolic complexes have a positive effect on the growth and development of plants, forming their protective, adaptogenic, and anti-stress properties. The aim of the study was to research the fatty acid composition of lipids in the microbial bioformulations Sporazyn and Ecophosphoryn, as well as in corn seedlings, under the influence of seed inoculation with microbiological complexes. Methods. Seeds and seedlings of corn of the interlineage hybrid of lines 1-Ak026 and 2-Ak033 were treated with Microbiological Complex 1 (MC1), includes bioformulations Sporazyn, Averkom, Phytovit, and Microbiological Complex 2 (MC2) based on Ecophosphoryn. Lipids from the analyzed samples were extracted by the Folch method. Hydrolysis and methylation of fatty acids from lipids extracted from corn seedlings were conducted in accordance with DSTU ISO 5509-2002, followed by analysis using the GC method. Results. The content of saturated and unsaturated fatty acids in the lipid complex of Sporazyn and Ecophosphoryn was found to be at a similar level. Ecophosphoryn differed from Sporazyn in the increased content of monounsaturated and omega-9 fatty acids. The lipid complex of Sporazyn had a higher content of polyunsaturated and omega-6 fatty acids than Ecophosphoryn. The impact of microbiological complexes on the sowing properties of corn seeds was identified. The application of MC1 (Sporazyn, Averkom, Phytovit) enhanced corn seed germination and germination energy by 6%. Under the influence of MC2 (Ecophosphoryn, Averkom, and Phytovit), germination rates and germination energy increased by 8.3 and 6.4%, respectively, compared to uninoculated seeds. The Alysinas of the lipid complex in corn seedlings identified 21 fatty acids, with their quantitative composition varying based on the applied microbiological complex. Conclusions. Under the influence of MK1, the content of behenic, caproic, and cis-13,16-docosadienoic acids increased by 2.1-fold, 7.8-fold, and 8.3-fold, respectively. In contrast, MC2 resulted in a decrease in their content by 1.4, 1.5, and 1.7-fold. Similar trends were observed in lignoceric, myristic, and palmitic acids. Seed treatment with MC1 enabled the detection of caprylic, capric, and lauric acids, which were absent in both the control and MC2-treated groups. Inoculation with both microbiological complexes led to an increase in linolenic (by 0.04–0.33%) and heptadecenoic (by 0.01%) acid content, while reductions were noted in oleic (by 0.43–9.76%) and arachidonic (0.02–0.05%) acids.
Hydrogel materials based on polyvinyl alcohol (PVA) and hyaluronic acid (HA) have a high potential for use in treating infected wounds due to their biocompatibility, moisturizing properties, and modifiability. The aim of this article is to create hydrogel composites based on PVA with varying contents of hyaluronic acid and ZnO nanoparticles and to evaluate their antimicrobial activity. Methods. The structure of ZnO-containing hydrogels was studied by wide-angle X-ray diffraction using an XRD-7000 diffractometer. The size of ZnO nanoparticles and their distribution in the PVA-HA polymer matrix were analyzed using a JEM-1230 transmission electron microscope. The antimicrobial activity of hydrogels PVA-HA-ZnO was evaluated using the disk diffusion method against the opportunistic pathogens S. aureus, S. epidermidis, E. coli, and P. aeruginosa. Results. Analysis of microphotographs of PVA-HA-ZnO hydrogels containing 0.1 mass% ZnO, obtained by freezing for 6 h, showed the formation of ultrafine nanoparticles statistically distributed within the polymer matrix during the material synthesis process. The antimicrobial activity of hydrogel materials made from PVA, with varying concentrations of hyaluronic acid (3%, 5%, and 9%) and zinc oxide nanoparticles was evaluated. The concentration of ZnO in the hydrogels ranged from 0.05 to 1.0 mass%. Testing was conducted on opportunistic microorganisms, including Gram-positive bacteria (S. aureus, S. epidermidis) and Gram-negative bacteria (E. coli, P. aeruginosa). It was found that the samples demonstrated a concentration-dependent antimicrobial effect. Samples with a higher HA content (9 %) exhibited greater antibacterial activity, particularly against S. epidermidis. Biopolymer hydrogel materials containing higher concentrations of ZnO (0.5%–1.0%) showed effective antimicrobial activity against Gram-positive bacteria such as S. aureus and S. epidermidis. No antimicrobial effects were observed against Gram-negative bacteria, including E. coli and P. aeruginosa, in any of the tested samples. The antimicrobial activity of PVA-based hydrogel materials without added hyaluronic acid was also evaluated. These materials contained zinc acetate salts (Zn(OOCCH₃)₂), which were not reduced to form nanoparticles. The zinc acetate concentration recalculated as ZnO content was 1.0 mass%. Hydrogels containing zinc acetate were found to be more effective against Gram-positive bacteria, such as S. aureus and S. epidermidis. They showed significant effectiveness against E. coli, a Gram-negative bacterium, but were not effective against P. aeruginosa. Conclusions. The results confirm that the developed hydrogel materials have antimicrobial properties and hold promise as bioactive wound dressings for treating infected wounds. Further modification of the composition — particularly through the addition of nanoparticle mixtures, antibiotics, or antimicrobial peptides — may broaden the activity spectrum and enhance their effectiveness against multidrug-resistant microorganisms.
Pectinases are a diverse group of enzymes responsible for the depolymerization and modification of plant cell wall polysaccharides. While bacterial and ascomycete pectinases are well studied and widely applied, the enzymatic potential of Basidiomycota remains underexplored. This review analyzes over 70 species of Basidiomycota and summarizes the genetic diversity of pectinase-encoding genes (over 100 genes associated with pectolytic activity), belonging to the CAZy families GH (8–78 genes, e.g., GH28 for polygalacturonases), PL (up to 24 genes, e.g., PL1 and PL3 for pectin/pectate lyases), and CE (up to 19 genes, e.g., CE8 and CE12 for pectinesterases). Special attention is given to the role of cultivation conditions – substrate type and concentration, temperature, pH, nitrogen supplementation, and co-cultivation – in regulating enzyme biosynthesis and activity. Pectinolytic activity varies widely (0.05 µmol/min/mL to 1163.8 units/gsubstrate), with white-rot fungi achieving the upper range. The most promising producers are from the genera Pleurotus, Trametes, and Lentinula. The review also covers isolation methods, including ammonium sulfate precipitation, dialysis, ion-exchange, and gel-filtration chromatography (purification factors 2.4–10.5, recovery 21–65%), and biochemical properties of basidiomycete pectinases, which exhibit moderate thermostability (40–60 °C optima), acidic pH optima (3.5–6.5), glycoprotein structure, and multiple isoforms. These enzymes show promising properties for fruit juice extraction, clarification, tissue maceration, and bioconversion of agro-industrial wastes. Therefore, Basidiomycota represents a valuable but insufficiently characterized source of industrial pectinases, requiring further study of new strain selection, cultivation optimization, and large-scale enzyme applications.
On November 27, 2025, at the age of 86, Ivan Gavrylovych Skrypal, Doctor of Biological Sciences, Professor, Corresponding Member of the National Academy of Sciences of Ukraine, Honored Worker of Science and Technology of Ukraine, and Laureate of the State Prize of Ukraine in Science and Technology, passed away. The passionate heart of the outstanding microbiologist stopped beating.
Walnuts (Juglans sp.) are affected by a wide range of bacterial pathogens belonging to different taxa, and their accurate identification is necessary for understanding both the etiology of diseases and the development of effective control measures. Phylogenetic analysis based on the analysis of the 16S rRNA gene is widely used in bacterial taxonomy. However, taxonomic studies of pathogens of bacterial diseases of walnuts in Ukraine are poorly known. The aim of this study was to determine the taxonomic position of phytopathogenic bacteria isolated from walnuts (Juglans sp.) in Ukraine using comparative analysis of nucleotide sequences of the 16S rRNA gene. Methods. The 16S rRNA gene was amplified by universal primers pA and pH. Sequence assembly, editing, and alignment were performed using Multalin and Sequence Manipulation Suite software. The rate of the 16S rRNA gene nucleotide sequences similarity of isolated strains with homology nucleotide sequences of typical strains located in GenBank was established using the BLASTN program. Phylogenetic relatedness was established and graphically displayed using the MEGA program. Results. Phylogenetic analysis of 16S rRNA gene sequences showed that isolated Agrobacterium spp. strains have the highest percentage of nucleotide sequence similarity (99.4–99.9%) with Agrobacterium tumefaciens LGM 196. Nucleotide sequences of the 16S rRNA gene of isolated Xanthomonas spp. strains are 98.51–99.65% related to the identical sequence of Xanthomonas arboricola pv. juglandis NCPPB 411. Pseudomonas spp. isolates are phylogenetically related (98.31–99.51%) to Pseudomonas syringae pv. syringae UCM B-1027ᵀ and P. syringae pv. syringae ATCC 19310. Conclusions. The high level of similarity of the 16S rRNA gene sequences isolated from the type strains confirms their taxonomic affiliation to these taxa and emphasizes the importance of phylogenetic analysis in the taxonomy of walnut pathogenic bacteria. Comparative analysis of the 16S rRNA gene sequences in combination with phenotypic characteristics confirms that the bacteria isolated from walnut belong to the species Agrobacterium tumefaciens, Xanthomonas arboricola, and Pseudomonas syringae.
Nontuberculous or atypical mycobacteria represent a large group of saprophytic and potentially pathogenic bacteria that can cause mycobacteriosis in humans and animals. Tuberculous mycobacteria most commonly infect mammals, while atypical mycobacteria have a much wider host range, including mammals, fish, amphibians, reptiles, and birds. Some species of nontuberculous mycobacteria are the etiologic factor in the occurrence of anthropozoonoses. Animals transmit these diseases, and human infection occurs through direct contact with the carrier or through its biological waste. Currently, there is little information available in Ukraine on the spread of infections associated with atypical mycobacteria in animals kept as pets. The study aimed to investigate the species composition of mycobacteria that can potentially cause mycobacteriosis in exotic companion animals. The research was conducted from 2023 to 2025 at the Laboratory for the Study of Tuberculosis of the National Scientific Center “Institute of Experimental and Clinical Veterinary Medicine” (Kharkiv). Methods. A bacteriological method was used to examine 463 samples, including droppings from companion birds, cloaca swabs from five red-eared turtles, feces from an African hedgehog, and samples of internal organs from an ornamental duck and peacock. These samples belonged to 39 different species of animals. Results. Out of the 463 samples, 84.7% tested positive for mycobacteria. Of those, 1.4% were M. scrofulaceum, 1.9% were M. avium, and 96.7% were M. genavense. Additionally, a photochromogenic culture of M. kansasii was isolated from a parrot for the first time in Ukraine. Cryptosporidium (20.5%), non-acid-fast bacteria (83.5%), molds and yeast-like fungi (42.2%), and Cryptococcus (2.0%) were found in 76% of fecal samples. Microorganism cultures of M. avium and Nocardia sp. were isolated from ornamental ducks. Conclusions. The results of the study indicate that exotic birds, especially parrots, are most susceptible to M. genavense. Due to the danger posed by opportunistic mycobacterial species to exotic animal owners, routine examinations of exotic animals for mycobacteriosis are necessary, as is compliance with sanitary and hygienic requirements for their maintenance.
Convergence of artificial intelligence with bionanotechnology shifts the “green” microbial synthesis of nanoparticles from an empirical approach to rational, data-driven design, enhancing reproducibility and technological maturity of the processes. The aim of this work was to summarize current knowledge and outline the role of AI, machine learning, and deep learning methods in multifactorial optimization of biosynthesis conditions, prediction of nanoparticle properties prior to their production, guided self-assembly and engineering of producer strains, as well as in ensuring the safety of nanomaterials in line with the Safe-by-Design concept. Methods. Publications from 2020–2025 in PubMed, ACM, ScienceDirect, Google Scholar, and Scilit databases were analyzed, applying double screening and thematic synthesis. It was established that the use of AI significantly reduces the number of experiments, enables coordinated control of process parameters, ensures transfer of synthesis conditions between laboratory and pilot-scale setups, and allows ex-ante prediction of nanoparticle stability, bioactivity, and antimicrobial action. In particular, for La-doped ZnO nanoparticles, model accuracy reached R² ≈ 0.96. A promising direction is programmed self-assembly of nanoscale structures, algorithmic selection of surface functionalization, and control of the protein “corona,” which determines biocompatibility and immune response. Another important result is the unification of toxicological data and improvement of regulatory compliance of products owing to explainable AI methods and integration with real-time process analytical control, as well as process design with quality built in from the outset. Thus, the convergence of artificial intelligence and “green” microbial synthesis establishes a platform for precision engineering of biogenic nanomaterials with predictable properties, where strategic success depends on high-quality data, algorithm transparency, and interdisciplinary collaboration.
As plants grow, up to 40% of their photosynthetic products are released into the root zone. These root exudates have a significant impact on the formation of the plant rhizosphere microbiome. However, the effect of introduced microorganisms on plant root exudates is not well understood. The aim of this study was to determine the effect of Bacillus subtilis IMV B-7023 on the accumulation of exometabolites in the hydroponic environment of wheat plants. Methods. The study of the effect of B. subtilis on the accumulation of biologically active substances in root exudates was carried out on the wheat variety Shestopalivka. Morphometric parameters of plants were determined. Protein content in the medium was determined by the Bradford method, carbohydrates – by interaction with phenol and sulfuric acid, and phenols – by Folin-Cocalteu reagent. Results. It was shown that bacterization of wheat seeds with B. subtilis bacteria significantly increased the accumulation of carbohydrates, protein and phenols in the medium. The most noticeable effect on the accumulation of these compounds in the medium was observed after bacterization with a suspension containing 108 CFU/mL. Conclusions. Inoculation of wheat seeds with Bacillus subtilis IMV B-7023 significantly stimulates the accumulation of a few exometabolites in the plant growth medium: carbohydrates and protein and phenolic compounds.
The wide spread of multidrug-resistant bacteria species stimulates a search for alternative antimicrobial substances. Silver nanoparticles (AgNP) are among the leading substances possessing a great potential for such a purpose. At the same time, the current data about the possibility of some metal nanoparticles, including silver ones, to stimulate the horizontal transfer of antibiotic resistance genes stipulate the necessity to know the nanoparticles’ influence on the antibiotic resistance profile of microorganisms when studying the biological activity of synthesized nanomaterials. The aim of the study was to evaluate the antimicrobial activity of synthesized AgNP against the test strains and Escherichia coli clinical isolates – causative agents of infectious diseases of farm animals – and to estimate the nanoparticles’ effectiveness in overcoming the antibiotic resistance and colicinogenic activity of E. coli isolates. Methods. AgNPs were synthesized by the chemical reduction method. Antimicrobial activity of the synthesized AgNP was tested via the method of serial dilutions in agar using E. coli ATCC 2592, Staphylococcus aureus MRSA ATCC 43300, Pseudomonas aeruginosa ATCC 27853, Bacillus subtilis ATCC 6633 test strains, and 12 E. coli clinical isolates. The alkaline lysis by the method of Birnboim and Doly followed by agarose gel electrophoresis was used for plasmid DNA screening in E. coli clinical isolates. Disk diffusion assay was used for bacteria antibiotic susceptibility testing. The ability of E. coli clinical isolates to produce colicins was studied by the method of deferred antagonism by Fredericq. Results. AgNP with an average particle size of 30 nm and spherical shape were synthesized. AgNP were characterized as noncytotoxic and nongenotoxic for eukaryotic cells. Antimicrobial activity of AgNP was revealed on the test strains as well as E. coli strains isolated from the pathological material of farm animals (swine, cattle). The changes in the profile of antibiotic resistance and colicinogenic activity were revealed after the treatment of bacteria cells by AgNP at concentrations of 25 and 50 μg/mL. Conclusions. The revealed properties make synthesized AgNP a great alternative antimicrobial substance with the possibility to overcome antibiotic resistance and colicinogenic activity of E. coli clinical isolates.
