Petruk T. Synthesis and biological activity of Streptomyces avermitilis avermectins complex

The thesis is devoted to study of Streptomyces avermitilis UCM Ac-2161 and its variants ability to avermectins synthesis and to research of avermectins complex biological activity. It has been received highly productive variant S. avermitilis UCM Ac-2177 using Ac-2161 variability, an ultraviolet and N-methyl-N'-nitro-N-nitrozoguanidin. Avermectins complex Avercom produced by this variant contained 40% of fraction B1 that had nematocidic activity. It is established that S. avermitilis UKM Ac-2177 active production of avermectins is observed under cultivation at the presence of 7% of glucose. Na acetate in the number of 0,5% increases of avermectins synthesis by an 16%. The regulators of plant growth as Ivin (100 ?l/ml) stimulate the avermectins production by 26% accordingly. Direct connection between avermectins accumulation in streptomycete biomass and lipids fractions, such as triglyceride, phospholipids and sterols is established. Fatty acids with carbon atoms in the number from С4 up to С10 were found out for the first time in lipids fatty-acids structure of S. avermitilis. The entering of S. avermitilis UCM Ac-2177 biomass, cultural liquid and Avercom in different concentration separately to soil increased the quantity of pedotrophic, amylolytic, phosphorus immobilizing and amonificating microbes. It was shown, for the first time, that Avercom is able to reveal not only nematocidic but phytostimulating activity too.