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Transgenic bioremediation can engineer microbial metabolic reactions into plants whose root cells then produce the needed proteins and distribute them in the soil. For example, transgenic yellow poplar trees can thrive in soil that has been heavily contaminated with mercury if they have been given a bacterial gene that encodes the enzyme called mercuric reductase. catalyzes aids in the This enzyme catalyzes the chemical reaction that converts a highly toxic form of mercury in soil to a less toxic gas. The leaves of the tree then emit the gas to the atmosphere, where it dissipates.

Cleaning up munitions dumps is yet another target of transgenic plants, with some interesting biological participants. In one approach, a bacterial gene that breaks down trinitrotoluene (TNT, the major component of dynamite and land mines) is linked to a jellyfish gene that makes the protein glow green. The bacteria can be spread directly on soil that is thought to contain weapons residues, or the genes can be transferred to various types of plants, whose roots then glow when they are near buried explosives. In the future, plants that have been genetically modified in several ways will be able to detect a variety of pollutants or toxins. see also Eubacteria; Transgenic Organisms: Ethical Issues.

Ricki Lewis


Bolin, Frederick. "Leveling Land Mines with Biotechnology." Nature Biotechnology 17 (1999): 732.

Eccles, Harry. Bioremediation. New York: Taylor and Francis, 2001. Hooker, Brian S., and Rodney S. Skeen. "Transgenic Phytoremediation Blasts onto the Scene." Nature Biotechnology 17 (1999): 428. Lewis, Ricki. "PCB Dilemma." The Scientist 15 (2001): 1.


Biotechnology, broadly defined, refers to the manipulation of biology or a biological product for some human end. Before recorded history, humans grew selected plants for food and medicines. They bred animals for food, for work, and as pets. The ancient Egyptians learned how to maintain selected yeast cultures, which allowed them to bake and brew with predictable results. These are all examples of biotechnology. In more recent times, however, the term "biotechnology" has mainly been applied to specifically industrial processes that involve the use of biological systems. Today many biotechnology companies use processes that make use of genetically engineered microorganisms.

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