Evaluation of growth-stimulating activity of microorganisms isolated from the soil of Akmola region

A promising direction of biological agriculture is the use of the potential of useful soil and rhizospheric microflora, among which nitrogen-fixing and phosphate-mobilizing natural microorganisms occupy a significant place. Biologics created based on soil microorganisms make it possible to change approaches in the technology of growing agricultural plants. When selecting strains of potential producers of biological products, an important aspect is the ability to have a positive effect on the growth and development of plants, providing them with mineral nutrition, adaptation to various stresses, protect soils from depletion, restore their natural fertility and maintain the biological diversity of plant communities. The aim of the study was to select promising microorganisms with high growth-stimulating activity against crops such as wheat and lentils. As a result of the primary screening, 76 isolates of soil bacteria were isolated, 16 of which were selected as the most active isolates exhibiting pronounced antimicrobial properties. Further, 7 strains of microorganisms were selected from them (D.acidovorans Ш-1, St.maltophilia КЖ-1, B.cereus ТБ-1, E.cloacae КБ-2, E.ludwiqii ТБ-2, E. cloacae ШБ-2, E.cloacae Т-3), which showed a high degree of germination of plant seeds. It was found that the bacterial suspension of each of the strains P.fluorescens АК-4, St.epidermidis СhK-4, B.cereus ТБ-1, E.cloacae КБ-2, E.ludwiqii ТБ-2, E.cloacae ШБ-2, E.cloacae Т-3 has a high growth- stimulating effect on the growth performance of wheat. When treating lentil seeds with a culture liquid of each of the strains B.cereus ТБ-1, E.cloacae КБ-2, E. ludwiqii ТБ-2, S.marcescens ТК-2, E.cloacae ШБ-2, E.cloacae Т-3 growth rates increased in all studied concentrations. As a result, the article identifies the most active microorganisms with high growth-stimulating activity and increasing the germination of plant seeds. Thus, the selected promising bacterial strains are recommended as a basis for the development of biological products that increase seed germination and stimulate the growth of agricultural plants.