Two bacteria found to be very useful in genetic engineering are
Bacillus thuringiensis is a very important bacterium which is used for its insecticidal properties. The gene of that confers insecticidal ability to the bacterium also known as the Cry gene is incorporated into the target host by the technique of genetic engineering. E coli has been extensively used for genetic engineering in animals. E.g The human variant of insulin is produced within the bacteria by the technique of recombinant DNA technology. By producing insulin this way, the cost to patients has dramatically dropped and the problem of immunological side effects have been disappeared. Therefore both Bt and E Coli are useful agents in genetic engineering.