Ecological Systems and Devices Annotation << Back CHARACTERISTICS OF PHYTOTOXICITY, ANTAGONISTIC AND ANTIOXIDANT ACTIVITY OF ACTINOMYCETES OF THE ARID ZONE L.N. Grigoryan, Yu.V. Bataeva, A.V. Fedotova, L.V. Yakovleva The phytotoxicity, insectoacaricidal and antioxidant activities of suspensions and extracts of actinomycete strains Streptomyces carpaticus RCAM04697, Nocardiopsis umidischolae RCAM04882, Nocardiopsis umidischolae RCAM04883 were studied. Phytotoxicity and insecticidal activity of suspensions and extracts of strains were studied at two concentrations: 0.5 mg/1 ml and 1 mg/1 ml. The phytotoxic properties of the suspension and extracts of the studied bacterial strains were studied by the method of inhibiting the growth of the radish root (Rarhanus sativus). Suspension and extracts of the strains S. carpaticus RCAM04697, N. umidischolae RCAM04882, N. umidischolae RCAM04883 were tested for insectoacaricidal activity under laboratory conditions, taking into account the double concentration of extracts (1 mg/1 ml and 0.5 mg/1 ml) against melon aphid (Aphis gossypii Glover.) and spider mites (Tetranychus urticae Koch.). The study of antioxidant activity and component composition of metabolites of suspensions and extracts of the three studied strains was carried out in 6 variants (suspension, water-alcohol extracts in three ratios (20:80; 50:50; 80:20), methanol and hexane extracts) with a concentration of 1 mg /1 ml. An analysis of the data we obtained showed that at 24 hours of recording, in almost all variants of the experiment, a mass death of A. gossypii and T. urticae was observed. S. carpaticus RCAM04697 is one of the effective strains of actinomycetes, in which the highest indicators of toxicity were found in relation to these test objects. It has been established that all variants of the extracts of the three strains are not toxic to plants, and the concentration of 1 mg/1 ml exhibits high phytostimulating activity. Suspension (88.8 %) and water-alcohol extract (76.0 %) of S. carpaticus RCAM04697 showed the highest antioxidant activity. The maximum antioxidant activity of N. umidischolae RCAM04882 was found in hexane and water-alcohol (80:20) extracts and amounted to 63.8 % and 71.4 %, respectively. It has been established that the strains of S. carpaticus RCAM04697, N. umidischolae RCAM04882, N. umidischolae RCAM04883 have high biological activity and can be used as the basis of microbiological preparations for agroecosystems. Keywords: actinomycetes, metabolites, phytotoxicity, insectoacaricidal activity, antioxidant properties. DOI: 10.25791/esip.3.2023.1359 Pp. 30-39.