What are transgenic bacteria ? Illustrate using any one example.

Transgenic bacteria are those bacteria whose DNA is manipulated to possess and express an extra (foreign) gene .

Example. Transgenic bacteria like E.coli which produces insulin. This bacteria is genetically manipulated by introducing two DNA sequences corresponding to A and B chains of human insulin in plasmids of E. coli to produce insulin chains. Chains A and B produced separately are extracted and  combined by disulfide bonds to form human insulin.