[The quantitative determination of Bacillus thuringiensis beta-exotoxin in insecticidal biopreparations]

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.