[The quantitative determination of Bacillus thuringiensis beta-exotoxin in insecticidal biopreparations]. / Kolichestvennoe opredelenie beta-ékzotoksina Bacillus thuringiensis v insektitsidnykh biopreparatakh.

A method of quantitative determination of beta-exotoxin content in liquid and dry bioformulations has been developed. The method includes a thin-layer chromatography to isolate beta-exotoxin from accompanying nucleotides, the further desorption of a single beta-exotoxin spot by water and to carry out spectrophotometry at 259 and 330 nm. beta-exotoxin content in industrial formulations bitoxibacillin and turingin I has been determined. The results obtained correspond to the NMR 1H spectroscopy data within the experimental errors. The relative error is 1-2%. The method sensitivity of 0.05 mg/ml. beta-exotoxin content at biotechnological stages of bitoxibacillin production has been determined.

[The role of bitoxibacillin components in the manifestation of its biological activity]. / Opredelenie roli komponentov bitoksibatsillina v proiavlenii ego biologicheskoi aktivnosti.

New methods were developed and applied to quantitative determination of beta-exotoxin and antibiotic activity of delta-endotoxin with respect to Micrococcus spp. in bitoxibacillin (BTB) and the fermentation broths prepared under industrial conditions. The biosynthesis of beta-exotoxin in the period of its maximum accumulation during the fermentation was estimated. It was shown that the primary biological effect of BTB on insects consisted in the actions of beta-exotoxin and delta-endotoxin. Biological activity of each of the entomocidal components of the entomocidal components of BTB did not practically correlated with the number of viable spores. There was a correlation between the antibiotic activity of crystalline B. thuringiensis subsp. thuringiensis solutions and the insecticidal activity of the entomopathogenic preparations. Determination of beta-exotoxin and antibiotic activity of delta-endotoxin might be used as a complex procedure for testing the quality of BTB. The method for estimating antibiotic activity of the crystal solutions allowed one to assay the biological activity of other preparations based on Bacillus thuringiensis non-synthesizing beta-exotoxin.