Eurasian Journal of Applied Biotechnology

The Bacteroides fragilis toxin (bft) Gene: Its Role in Virulence, Regulation, and Disease

A. Bekbayeva , B.S. Kongyr, E.V. Zholdybayeva, S.S. Kozhakhmetova — Tue, 30 Jun 2026 00:00:00 +0500

Bacteroides fragilis can be divided into two different groups of strains: an enterotoxigenic strain (ETBF) that has a pathogenicity island and the Bacteroides fragilis toxin gene (bft) and a non-toxigenic strain (NTBF) that does not have a pathogenicity island and the bft gene. Recent studies have shown that there is a correlation between the presence of the bft gene in enterotoxigenic Bacteroides fragilis (ETBF) strains and various gastrointestinal disorders, including colorectal cancer and inflammatory bowel disease. Due to its ability to disrupt the intestinal epithelial barrier, promote chronic inflammation, and affect carcinogenesis, the presence and expression of bft significantly contribute to the pathogenicity of ETBF. This review provides an analysis of the genetic structure, allelic variants, and regulatory mechanisms of bft. A membrane protein vital to cell adhesion, E-cadherin, is disrupted by Bacteroides fragilis toxin, resulting in disruption of epithelial integrity and facilitating bacterial entry. BFT also stimulates important intracellular signaling pathways, including mitogen-activated protein kinase (MAPK) and nuclear factor kappa-light chain enhancer of activated B cells (NF-kB). These signaling pathways significantly influence both cellular transformation and inflammatory responses. This review also highlights advances in diagnostic methods and innovative therapeutic approaches, such as the development of allosteric inhibitors that can block BFT activity. Although much has been learned about the regulation and function of the bft gene, there are significant gaps in understanding the environmental factors that lead to gene upregulation and its molecular interactions. Future research should aim to elucidate these mechanisms to facilitate the development of targeted therapies.

EFFICIENCY OF USING BIOLOGICAL PREPARATIONS AND MINERAL FERTILIZERS IN CULTIVATION OF SUGAR SORGHUM IN THE SOUTHERN REGIONS OF KAZAKHSTAN

Tue, 30 Jun 2026 00:00:00 +0500

This article presents the results of studies on the influence of biological preparations and mineral fertilizers on the productivity of sugar sorghum cultivated in the southern regions of Kazakhstan. During a five-year field experiment (2019–2023), the complex effect of biologically active substances (Celeste Top, Gumi 20, Potassium Humate) and doses of nitrogen-phosphorus fertilizers (N₃₀P₃₀, N₆₀P₆₀, N₉₀P₉₀) on field germination, photosynthetic activity and green mass yield of sugar sorghum of the Kazakhstanskoye 20 variety was studied. It was found that the greatest effect is achieved with the combined use of Potassium Humate and fertilizers at a dose of N₉₀P₉₀, which provides a yield increase of 5.4 t/ha compared to the control. Optimal doses and combinations of biopreparations with mineral fertilizers have been determined, providing the maximum economic effect in the cultivation of sugar sorghum in arid conditions.

Evaluation of the immunobiological properties of an oral briquette rabies vaccine in foxes

Tue, 30 Jun 2026 00:00:00 +0500

Rabies remains one of the most dangerous zoonotic infections maintained in natural reservoirs among wild carnivorous animals. Despite the high efficacy of inactivated vaccines in domestic animals, rabies control in wildlife requires the use of oral vaccines capable of providing mass immunization of naturally susceptible species. The aim of the present study was to evaluate the immunogenicity, safety, and protective efficacy of an oral briquetted rabies vaccine tested in naturally susceptible carnivorous animals. Clinically healthy rabies-seronegative foxes were used in the experiment. To assess immunogenicity, animals received a single oral administration of a briquetted vaccine containing a fixed rabies virus strain. Vaccine safety was evaluated using an increased dose (10 baits per animal). The dynamics of the humoral immune response were assessed using the mouse neutralization test and ELISA. Protective efficacy was determined by challenge infection with the CVS test strain. The results demonstrated that the vaccine was readily consumed by the animals and did not cause clinical adverse reactions or deviations from physiological norms. Vaccinated animals developed a pronounced humoral immune response, with mean virus-neutralizing antibody titers exceeding the protective level of 0.5 IU/ml and reaching peak values on day 21 post-immunization. Following challenge infection, all vaccinated animals survived and showed no clinical signs of rabies, whereas control animals developed the paralytic form of the disease with a fatal outcome. Thus, the obtained data demonstrate the high immunogenicity, safety, and protective efficacy of the oral briquetted rabies vaccine and confirm its potential for use in oral immunization programs targeting carnivorous wildlife species and the control of natural rabies foci.

DESIGN, EXPRESSION AND PURIFICATION OF VIAAT PROTEIN CONSTRUCT FOR CRYO-EM STRUCTURAL ANALYSIS

M. Patapovich, N. Lukashenko, A. Yantsevich — Tue, 30 Jun 2026 00:00:00 +0500

In GABAergic neurons GABA is being transported into the synaptic vesicles by unique vesicular inhibitory amino acid transporter (VIAAT). Dysfunction of GABAergic system has been implicated into various diseases of neurological spectrum, making VIAAT a reasonable target for treatment. In order to develop specific modulators of VIAAT functioning, a well resolved three-dimensional structure of the transporter is needed. Such data is absent for the moment due to protein behavior in course of cryo-electron microscopy. In this work, interspecies VIAAT hybrid protein was designed in order to improve overall stability and introduce compatibility to the Fab fiducial marker, thus facilitating structure determination. Each variant consisted of the main part of drosophila VIAAT, in which the C-terminal part was replaced with the corresponding Fab binding region of human VIAAT. Interspecies parts of the hybrid protein were linked using a helical linker. Total of 9 hybrid protein variants were expressed in HEK293F cell line. Variants able to bind Fab were selected for further purification and applied to cryo-EM for structure determination. Three-dimensional data can contribute to the understanding of VIAAT structural organization which, in turn, facilitate the search for specific functional modulators as the perspective therapeutic agents for a wide variety of diseases.

BRYOPHYTE FLORA OF THE KARKARALY REGION (KARAGANDY REGION, KAZAKHSTAN): SPECIES COMPOSITION AND HABITAT DISTRIBUTION

Tue, 30 Jun 2026 00:00:00 +0500

Bryophytes represent an important yet insufficiently studied component of terrestrial biodiversity in Central Kazakhstan. This study investigates the species composition and phylogenetic relationships of mosses in Karkaraly National Park (Karaganda Region), a forest–steppe enclave within the arid landscapes of the Kazakh Uplands. A total of 29 moss samples were collected and analyzed using an integrative approach combining microscopic morphological examination and molecular identification based on nuclear ribosomal ITS1 and ITS2 markers. Nine species belonging to seven families and four orders were identified, including Ceratodon purpureus, Syntrichia ruralis, Dicranum muehlenbeckii, Dicranum schljakovii, Polytrichum juniperinum, Polytrichum piliferum, Sanionia uncinata, Pylaisia polyantha and Abietinella abietina. Phylogenetic analysis using the Maximum Likelihood method confirmed species-level identification and revealed consistent clustering of samples within their respective genera. The detected assemblage reflects the ecological heterogeneity of the Karkaraly Mountains, where microclimatic variation supports both xerophytic and mesophilous moss species. This study represents one of the first integrative analyses combining morphological and molecular (ITS1 and ITS2) approaches to identify mosses in Central Kazakhstan. The results provide novel baseline data on species composition and phylogenetic relationships of bryophytes in the Karkaraly region and highlight its role as a refugium for both xerophytic and mesophilous taxa within a semi-arid landscape.

Isolation of Bacillus spp. Strains from soil biocenoses and their screening for phytase activity

M. Astrakhanov, K. Baltin, B. Bizhanova, K. Maksutova, B. Khassenov — Tue, 30 Jun 2026 00:00:00 +0500

Phosphorus is a component of phosphates, nucleic acids, necessary for the synthesis of proteins, phospholipids, metabolic enzymes, and intracellular buffers. Therefore, all feeds must contain phosphorus in digestible form. In plant-based feeds, about 60-90% of phosphorus is found in the form of phytinic acid and its salts - phytates, which have anti-nutritive properties, which affects the maintenance of animals with a simple stomach: poultry, pigs, fish. Phytate, which is a phosphorus-containing waste from poultry farms, pig farms, and pond farms, negatively impacts the environmental situation. Fitases, which are myo-inositol phosphohydrolases, catalyze the hydrolysis of phytin acid to monophosphate and intermediate myo-inositol phosphate, which allows for the simultaneous solution of three problems: eliminating the need for feed phosphorus, reducing the anti-nutritional value of feed, and improving the ecological situation near poultry farms, farms, and pond facilities. From soil samples collected from the territories of the Akmola, Turkestan, Kyzylorda, and Zhambyl regions, 10 isolates of microorganisms belonging to the species Cytobacter oceaanisediminis, Peribacillus simplex, Bacillus mojavensis, Bacillus cereus, Bacillus pumilus, Bacillus thuringiensis, Bacillus megaterium, Bacillus subtilis, Bacillus paralicheniformis were isolated. Screening showed that 9 of these strains are capable of hydrolyzing phytinic acid, indicating their phytase activity. Of these, Bacillus mojavensis SH1 and Bacillus megaterium 1POL strains were selected as the most active strains for research. The study of biochemical properties showed that the phytase from B. mojavensis SH1 is active in the temperature range of 30-37°C and pH 8.0, while the phytase from B. megaterium 1POL is active at 60°C and pH 4.0-7.0. Phytase activity was 0.34 U/ml for the B. mojavensis SH1 and B. megaterium 1POL strains. The obtained results indicate the prospects of using B. mojavensis SH1 and B. megaterium 1POL strains as bacterial phytase producers.