Tsyganenko K. The evaluation of antibiotic and toxigenic potential of some species of genera Aspergillus Mich.

The dissertation is devoted to study and estimation of antibiotic and toxigenic potential of some micromycetes' species of the Aspergillus genera. 128 strains of Aspergillus genera were investigated. 26 % of strains had a wide spectrum of antibiotic action and high phytotoxic activity. And 5 % of strains were inactive. Two strains of A. parvulus (3142 and 1813) were investigated for phytotoxic activity against plants seeds. It was shown, that the highest bioactivity of A. parvulus 3142 cultural filtrate observed during submerged cultivation. As a source of a carbon and nitric feed glucose and NaNO3 (in the ratio 20:1, accordingly) were used. Temperature was 26 oC, pH 4.8, mass transfer with Kv = 0.3 gO2/litre per hour, at the light. The approach of allocation, fractionation and clearing of bioactive metabolite from cultural filtrate of A. parvulus 3142 was developed. The method is based on two-stage column chromatography. Received crystal preparation did not contain nitrogen, sulfur and halogens, destroyed at 273 oC, has a maximum of absorption in the UV part of spectrum (at 256 nm), its minimal suppressing concentration in relation to B. subtilis 617 was 0.14 mg/ml, and it was not toxic for animals.