BIOTECHNOLOGICAL POTENTIAL OF SOIL MICROFLORA

Abstract

The isolation of autochthonous strains for the creation of microbial preparations on their basis during crop cultivation is an ecologically feasible technique for obtaining high-quality competitive crop production, preserving soil fertility and the environment. For effective application of biopreparations it is necessary to carry out in-depth studies of relationships in the system soil - microorganisms - plant taking into account ecological laws of its functioning. Laboratory of molecular-genetic and microbiological methods of the Federal Research Center “Kazan Scientific Center of the Russian Academy of Sciences”, having modern high-precision equipment, is focused on solving the problems of the effectiveness of biopreparations in their use in the open ground, as well as the introduction of molecular-genetic methods for the analysis of consortia of microorganisms, characterization of the most promising strains and the development of monitoring systems for phytopathogens in solving plant protection problems. The microflora of cultivated plants (more than six thousand bacterial isolates) is studied in detail and consortia consisting of useful and compatible autochthonous microorganisms are created. New strains - agents of biological plant protection - are isolated in model systems. Bacterial strains that passed all stages of selection (determination of different types of enzymatic activities, exclusion of repeats and pathogens, verification of antagonistic and colonizing properties, ability to synthesize indole-3-acetic acid (IAA)) are represented by four conventional groups: (1) bacteria capable of colonizing the plant root system; (2) bacteria antagonists of phytopathogenic fungi; (3) bacteria producers of PPIs; and (4) bacteria that stimulate plant growth through their enzymatic activities. A specific consortium is assembled from four strains (one from each group) to test compatibility. Step-by-step rapid diagnosis of promising strains allows to reduce the time of work on isolation of plant biodefense agents without loss of quality of isolated strains. DNA fingerprinting of isolates using BOX-PCR significantly reduces the number of isolates without loss of strain diversity by removing clones of the same strain in a sample. Identification can eliminate potentially pathogenic strains whose use is undesirable. In the process of research, biosynthetic genes and gene clusters involved in the production of a wide range of secondary metabolites and enzymes were identified, which confirms the validity of the choice of these strains as potential biocontrol agents and their further study for the creation of biologics. The samples of biopreparations of complex action were created, the effectiveness of which was experimentally proved in model systems.