Adsorption formulation of the insecticidal protein from Bacillus thuringiensis

Bacillus thuringiensis is the most widely used commercial biopesticide in the combat against harmful insects, both in the agricultural and public health spheres due to its environmental safe. The disadvantage of Bt commercial formulations that parasporal crystals and spores are rapidly degraded by environmental factors after application has stalled Bt development to a great extent. As the adsorbed Bt proteins on clay minerals have higher insecticidal activity and longer persistence time in the field, therefore, the adsorption of Bt proteins provides a new approach for the preparation of long-term formulations of Bt. The persistence of Bt proteins is related to the pH of soil, the higher the pH of soil, the lower the persistence of Bt proteins. The 2:1 Si:Al swelling clays are the suitable adsorbents for preparing the adsorption formulations as they protect Bt proteins from ultraviolet irradiation damage.