A rod-shaped bacterium (short Bt) from the order Bacillaceae. The name came from the fact that it was isolated in 1911 from a flour moth, which came from a mill in Thuringia. It is a soil bacterium that lives in the company of plant roots and contains a protein crystal that is toxic for certain insects. The toxins protect the roots from damage by insects. Genes transferred into crops cause the plants to independently produce Bt toxins. These are deadly on the larvae of insects of the orders of beetles, butterflies and fly (mosquitoes and flies). After being eaten by the larvae, it releases into its intestines and unfolds its deadly effect. In plants and vertebrates such. B. humans, however, the bacterium is ineffective and is completely biodegradable.