Discovered by bacteriologist Ishiwata Shigetane on a diseased silkworm in 1901. Later discovered on a dead Mediterranean flour moth, and first named Bacillus thuringiensis, by Ernst Berliner in 1915.
Today, Bacillus thuringiensis refers to a group of rod-shaped soil bacteria found all over the earth, that produce “cry” proteins which are indigestible by—yet still “bind” to—specific insects’ gut (i.e., stomach) lining receptors, so those “cry” proteins are toxic to certain classes of insects (com borers, com rootworms, mosquitoes, black flies, some types of beetles, etc.), but which are harmless to all mammals. At least 20,000 strains of Bacillus thuringiensis are known.
Genes that code for the production of these “cry” proteins that are toxic to insects have been inserted by scientists since 1989 into vectors (i.e., viruses, other bacteria, and other microorganisms) in order to confer insect resistance to certain agricultural plants (e.g., via expression of those B.t. proteins by one or more tissues of the transgenic plant). For example, the B.t. strain known as B.t. kurstaki, which is fatal when ingested by the European com borer was first (genetically) inserted into a com plant (via vector) in 1991 . B.t. kurstaki kills borers via perforation of that insect’s gut by proteins that are coded-for by the B.t. kurstaki gene. The vectors as listed above are entities that can take up and carry the DNA into plant or other cells. Vectors are DNA-carrying vehicles.