BRADYRHIZOBIUM JAPONICUM REACTION IN PURE CULTURE AND SYMBIOTIC SYSTEMS TO THE USE OF NANOCARBOXYLATES OF MICROELEMENTS

Objective. Study the influence of various concentrations of germanium, molybdenum, vanadium, cobalt, iron, copper and zinc on the growth dynamics of rhizobia, to select the most effective ones for studying their role as components of the digest medium in growing rhizobia and optimizing the formation and functioning of symbiotic soybean – Bradyrhizobium japonicum systems. Methods. Microbiological, physiological, spectrophotometry, gas chromatography. Results. It was found that the addition of most of the studied trace elements to the rhizobia growth medium had a positive effect on the growth dynamics of the bacterial culture. The exception was zinc nanocarboxylate, the introduction of which in the digest medium significantly reduced the growth of biomass bacteria. At the same time, irrespective of concentration, the most stimulating effect on the dynamics of growth of rhizobia in a pure culture was typical for the nanocarboxylates of iron, germanium and molybdenum. Their maximum action was developed at a concentration of 1:1000. These compounds are promising when adding rhizobia cultivating medium and studying their effect on the processes of forming and functioning of legume-rhizobial symbiotic systems. Analysis of the results of vegetation experiments showed that the use of iron, germanium and molybdenum nanocarboxylates as components of the rice growing medium at a concentration of 1:1000 positively influenced the processes of formation and functioning of symbiotic systems formed with the participation of various Bradyrhizobium japonicum strains – 634b and 604k, as well as on the growth of the vegetative mass of soybean plants. In this case, the most effective was germanium nanocarboxylate. Conclusion. The promising use of the active strain Bradyrhizobium japonicum 634b in combination with germanium nanocarboxylate in soybean cultivation has been experimentally proven to enhance the effectiveness of symbiotic systems.