Genetically modified bacteria

Genetically modified bacteria were the first organisms to be modified in the laboratory, due to their simple genetics.^[1] These organisms are now used for several purposes, and are particularly important in producing large amounts of pure human proteins for use in medicine.^[2]

History

The first example of this occurred in 1978 when Herbert Boyer, working at a University of California laboratory, took a version of the human insulin gene and inserted into the bacterium Escherichia coli to produce synthetic "human" insulin. Four years later, it was approved by the U.S. Food and Drug Administration.

Pharmaceutical production

• The drug industry has made use of this discovery to produce medication for diabetes.^[3] Similar bacteria have been used to produce clotting factors to treat haemophilia,^[4] and human growth hormone to treat various forms of dwarfism.^[5][6] These recombinant proteins are safer than the products they replaced. Prior to recombinant protein products, several treatments were derived from cadavers or other donated body fluids and could transmit diseases.^[7] Indeed, transfusion of blood products had previously led to unintentional infection of haemophiliacs with HIV or hepatitis C; similarly, treatment with human growth hormone derived from cadaver pituitary glands may have led to outbreaks of Creutzfeldt–Jakob disease.^[7][8]*

Other uses

Genetically modified bacteria can serve various purposes beyond producing medicinal compounds. For instance, bacteria which generally cause tooth decay have been engineered to no longer produce tooth-corroding lactic acid.^[9] These transgenic bacteria, if allowed to colonize a person's mouth, could perhaps reduce the formation of cavities.^[10] Transgenic microbes have also been used in recent research to kill or hinder tumors, and to fight Crohn's disease.^[11] Genetically modified bacteria are also used in some soils to facilitate crop growth, and can also produce chemicals toxic to crop pests.

GM bacteria have also been developed to leach copper from ore,^[12] clean up mercury pollution^[13] and detect arsenic in drinking water.^[14]

Bacteria-synthesized transgenic products

• Insulin
• Hepatitis B vaccine
• Tissue plasminogen activator
• Human growth hormone
• Ice-minus bacteria
• Interferon
• Bt corn

References

Further reading

• Karl Drlica. Understanding DNA and Gene Cloning: A Guide for the Curious (4th ed.). ISBN 978-0-471-43416-0.