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Transgenic Microorganisms

Commercial Application

Transgenic microbes have many commercial and practical applications, including the production of mammalian products. A company called Genentech was among the earliest and most successful commercial enterprises to use genetically engineered bacteria to produce human proteins. Their first product was human insulin produced by genetically engineered Escherichia coli. A variety of other human hormones, blood proteins, and immune modulators are now produced in a similar fashion, in addition to vaccines for such infectious agents as hepatitis B virus and measles.

Another promising application of genetically engineered microbes is in environmental cleanup, or biomediation. Scientists have discovered many naturally occurring genes that code for enzymes that degrade toxic wastes and wastewater pollutants in bacteria. Examples include genes for degrading chlorinated pesticides, chlorobenzenes, naphthalene, toluene, anilines, and various hydrocarbons. Researchers are using molecular cloning to introduce these genes from several different microbes into a single microbe, creating "super microbes" with the ability to degrade multiple contaminants.

Ananda Chakrabarty created one of the first microbes of this nature in the early 1970s. He introduced genes from several different bacteria into a strain of Burkholderia cepacia, giving it the ability to degrade toxic compounds found in petroleum. This microbe offered a potential alternative to skimming and absorbing spilled oil. Chakrabarty's genetically modified bacterium has never been used, however, due to public concerns about the release of genetically engineered microbes into the environment. The microbe did, on the other hand, play an important role in establishing the biotechnology industry. The U.S. Patent Office granted Chakrabarty the first patent ever for the construction and use of a genetically engineered bacterium. This established a precedent allowing biotechnology companies to protect their "inventions" in the same way chemical and pharmaceutical companies have done in the past.

Cynthia A. Needham


Glick, Bernard R., and Jack J. Pasternak. Molecular Biotechnology: Principles and Applications of Recombinant DNA, 2nd ed. Washington, DC: ASM Press, 1998.

Madigan, Michael T., John M. Martinko, and Jack Parker. Brock Biology of Microorganisms, 9th ed. Upper Saddle River, NJ: Prentice Hall, 2000.

Needham, Cynthia A., Mahlon Hoagland, Kenneth McPherson, and Bert Dodson. Intimate Strangers: Unseen Life on Earth. Washington, DC: ASM Press, 2000.

Snyder, Larry, and Wendy Champness. Molecular Genetics of Bacteria. Washington, DC: ASM Press, 1997.

Additional topics

Medicine EncyclopediaGenetics in Medicine - Part 4Transgenic Microorganisms - Moving Genes Between Species, Commercial Application