Aldan Shamukhan

Abiotic stress factors, including drought and salinity, severely limit crop productivity worldwide. Furthermore, the extensive use of herbicides, such as glyphosate, disrupts beneficial soil microbiota, further impairing crop growth. Plant growth-promoting bacteria (PGPB) represent a sustainable and efficient strategy to enhance crop yields, particularly under unfavorable environmental and soil conditions. In this study, we characterized Paenibacillus sp. JSM-10, newly isolated from glyphosate-exposed agricultural soil, for its stress tolerance and plant growth-promoting potential, including its morphology examined using complementary microscopy techniques. The strain tolerated up to 0.5 g/L glyphosate, 15 g/L NaCl, and 100 g/L polyethylene glycol (PEG-6000) without significant growth inhibition (p > 0.05), demonstrating robust resilience to such multiple abiotic stresses. Beyond its tolerance, the strain exhibited several beneficial characteristics, including indole-3-acetic acid (IAA) synthesis, siderophore production, and inorganic phosphate solubilization. Furthermore, both living cells and culture filtrates of JSM-10 exhibited a positive trend toward enhancing buckwheat growth under normal and saline conditions, with effect sizes ranging from Hedges’ g = 0.56−0.92. In addition, JSM-10 exhibited antagonistic activity against a range of pathogenic microorganisms, including Nigrospora oryzae, Bipolaris sorokiniana, Alternaria spp., and Escherichia coli. Altogether, these characteristics highlight the Paenibacillus sp. JSM-10 strain and its culture filtrates as promising candidates for application in organic farming aimed at promoting plant growth and improving stress tolerance via plant–microbe interactions.

The method of periodic updating (PU) or the periodic addition (PA) of fresh medium is considered as a promising technique for long-term and effective production of polyhydroxybutyrate (PHB) synthesized by different soil bacteria. In our previous studies, we reported PHB-producing potential of the Bacillus aryabhattai strain RAF 5 IMD B - 462 isolated from the chestnut soils in Astana city, Kazakhstan. The current study reports on the optimization of the RAF 5 cultivation using PU technology to obtain a high yield of PHB and biomass, as well as on the study of a membrane obtained on the basis of PHB. The accumulation of dense PHB granules in cell cytosol was confirmed by Transmission Electron Microscopy (TEM) analyses; more than 10 granules per cell were found in the cytosol of RAF 5. PHB was further extracted using the solvent extraction method. The highest PHB yield and biomass obtained after 72-hour incubation were 18.03 g/L and 20.04 g/L, respectively, when PU was applied. The highest PHB titer after 120-hour incubation was 3.76 g/L, when RAF 5 was growing in a conventional culture medium NB. The obtained PHB was further utilized to make a membrane sample which was subjected to water vapor, oxygen and carbon dioxide gas permeability analyses showing the promising results. In conclusion, this data proposes potential application might be utilized as a promising material to produce membranes.

Background/Objectives: Multidrug-resistant tuberculosis remains a critical public health challenge in Kazakhstan, yet the genomic determinants contributing to its emergence are still insufficiently understood. Although the quantity of genomic studies from Central Asia and the wider post-Soviet region has increased in recent years, the involvement of DNA repair and genome maintenance pathways in the development of resistance within Kazakhstan has not been comprehensively explored. Methods: In this study, we performed whole-genome analysis of 175 Mycobacterium tuberculosis clinical isolates collected across Kazakhstan between 2010 and 2022 to evaluate the contribution of single-nucleotide polymorphisms in DNA replication, repair, and recombination (3R) genes to the evolution of drug resistance. Results: Alongside well-established resistance mutations in gyrA, we identified recurrent variants in 3R-associated loci (genes involved in DNA replication, repair, and recombination)—including polA, uvrC and ligC—that were enriched among drug-resistant isolates, suggesting a broader role for genome maintenance pathways in facilitating resistance evolution under treatment pressure. Conclusions: These findings provide the first region-specific genomic insights into 3R gene variation in Kazakhstani M. tuberculosis isolates.