ANTAGONISTIC ACTIVITY OF BACTERIA ISOLATED FROM OLEA EUROPAEA L. RHIZOSPHERE AGAINST SOME PHYTOPATHOGENS
Babko A, Gromyko O, Tistechok S, Fedorenko V.
Ivan Franko National University of Lviv,
Department of genetics and biotechnology
e-mail: hr.anastasia.t@gmail.com
Phytopathogenic bacteria cause major economic losses in agriculture. These microorganisms affect the seeds and all organs of the plant during the growing season, disrupt the normal course of physiological processes, cause necrosis and fading of plant organisms. The number of fruits and the quality of production decrease in plants affected by phytopathogenic bacteria.
The attention of researchers is directed to the search for new bioactive compounds with antimicrobial action. Actinomycetes, especially Streptomyces sp., are producers of many biologically active compounds: antibiotics, enzymes, plant growth-promoting molecules. Such properties make these microorganisms interesting as agents of biological control of phytopathogens as well as the basis of biological products for stimulating plant growth.
The aim of this study was to identify actinobacteria strains capable to synthesize compounds with antibiotic action against phytopathogenic microorganisms. 166 actinomycetes isolates of the Olea europaea L. rhizosphere were used in the work. Pseudomonas syringae IMV B-8511, P. fluorescens 8573, P. savastanoi pv. phaseolicola IMV B-4012, Pectobacterium carotovorum IMV 8982, Xanthomonas campestris pv. campestris IMV B-80036 were used as the test-cultures to study antagonistic properties of isolated actinomycetes. The sensitivity of three species of pseudomonads was different: 36.7% of actinomycetes strains inhibited the growth of P. syringae IMV B-8511 and 30% of strains inhibited P. fluorescens 8573 and P. savastanoi pv. phaseolicola IMV B-4012. The antagonistic indexes (AI) of the most of strains had values between 1.0-3.0. 1.8% of the bacterial isolates had AI of 7.6-14.6 against P. fluorescens 8573 and 5.4% of them inhibited the growth of P. savastanoi pv. phaseolicola IMV B-4012 and had AI values of 3.1-4.0. P. carotovorum IMV B-8982 was the most resistant of the studied phytopathogens. This bacterium was inhibited by the 21.7% of the isolates with AI between 1.2-6.3. The least resistant was X. campestris pv. campestris IMV B-80036. 48.2% of the isolates inhibited its growth and showed AI in range of 1.1-14.3. 7.2% of the studied isolates inhibited the growth of all of the test strains. Actinomycetes strains 20-128 and 20-144 had the highest AI values.
Thus the following studies and analyzes of secondary metabolites will allow to identify the compounds that provide the antagonistic activity of these actinomycetes against the phytopathogenic bacteria.