ANTAGONISTIC ACTIVITY OF SOIL STREPTOMYCETES AGAINST PHYTOPATHOGENIC BACTERIAAND FUNGI

Abstract

Aim. The selection of soil active cultures of Streptomyces antagonists promising for the development of a biopreparation for plant protection against pathogens of fungal and bacterial diseases. Methods. Streptomycetes were isolated from the samples of soil on mineral medium Gause. The antagonistic activity of the selected isolates and collection strain of Streptomyces recifensis IMV Ac-5018 against phytopathogenic bacteria and fungi was tested by agar diffusion method; the antifungal activity of cultural liquid and supernatant of cultural liquid was determined by agar blocks method. The identification of the most active selected isolates to genus level was carried out by taking into consideration the morphological and cultural characteristics. Results. From 35 isolates of soil microorganisms the isolates №31 and №35 belonging to the genus Streptomyces showed high level and wide range of antagonistic action. Isolate №35 actively inhibited the growth of phytopathogenic fungi (Fusarium culmorum 50716, Cladosporium herbarum 16878, Fusarium moniliforme 23, Alternaria alternata 16, Aspergillus niger 25, F. oxysporum 12), the zones of growth inhibition were 15.0–24.5 mm. Isolate №31 actively inhibited the growth of phytopathogenic fungi (Fusarium culmorum 50716, Fusarium oxysporum 54201, Oidium thuckeri 11, Alternaria alternata 16) and phytopathogenic bacteria (Pseudomonas syringae pv. atrofaciens 8254, Pseudomonas syringae pv. lachrymans 7595, Xanthomonas campestris 8003), the zones of growth inhibition were 14.0–19.5 mm and 15.0–18.7 mm, respectively. The cultural liquid and supernatant of cultural liquid of S.recifensis IMV-Ac 5018, the isolates №31 and №35 inhibited growth of Fusarium culmorum 50716 (76.0–80.2% and 16.9–24.3%, respectively). Conclusions. The selected isolates can be regarded as promising microbial agents of biopreparation to protect the plants against fungal and bacterial diseases. The collection strain S. recifensis IMV Ac-5018 is a producer of glycopeptic plant growth stimulator, it also showed antifungal activity, allowing to use it in plant protection against diseases.