BSCS Biology: A Molecular Approach

Unit 3: Heredity: Continuity of Life

In the News

Seaweed Soaks Up Pollutants
Did you know that seaweed is a key ingredient in many consumer products such as ice cream, toothpaste, and air freshener? This algae also is a major food source in Asia. In the future, however, seaweed might take an active role in making water ecosystems cleaner and safer by acting as a sort of underwater bomb squad to diffuse unexploded weapons on the ocean floor.

Professors at Oregon State University and Northeastern University in Boston have developed a seaweed that can absorb TNT leaking from unexploded weapons in coastal areas. What's more, the seaweed might have the ability to soak up other organic pollutants as well.

Normally, TNT kills the red seaweed, called porphyra, on which the researchers are working. In 2002, the U.S. Office of Naval Research asked this group of professors to investigate whether they could modify porphyra so that it could neutralize TNT seeping from unexploded shells into the waters near naval training areas.

After study and testing, the group announced in February 2005 that the seaweed they have engineered is able to absorb TNT and break down the nitrogen that makes it so toxic. Because the seaweed neutralizes the pollutant, there is no need to gather and dispose of the seaweed after it has done its job. These findings could lead to wider use of seaweed as a pollution-control agent.

Fish farmers have long used naturally occurring seaweed to absorb some of the pollutants created during salmon farming and fish hatchery activities. The new seaweed could be a much more powerful tool. It could even be used to sop up PCBs (polychlorinated biphenyls) and other pollutants in the nation's river basins and estuaries.

There is a catch, however. The new seaweed is genetically engineered. To develop it, the researchers introduced a gene from a land-based bacterium that produces a TNT-detoxifying enzyme into poryphyra's DNA. The genetically altered porphyra produces the same enzyme.

Current regulations prevent the release of the genetically engineered version of poryphya into the wild. Most environmental groups oppose the practice in general, calling it biological pollution. As a result, researchers are now working on ways to breed TNT-eating strains of poryphra without using genetic engineering. They are using natural selection to develop the traits they are interested in. In fact, they already have had some success.

The naturally selected strains could be used widely to detoxify areas around environmentally sensitive locations, such as coral reefs. They could also be used as a kind of buffer around coastal areas where shellfish are farmed for human consumption.

Sources:

Seaweed in products:

http://home.howstuffworks.com/framed.htm?parent=question315.htm&url=http://philexport.org/members/siap/intro.htm

PCB:

http://www.answers.com/topic/pcb

General:

http://oregonstate.edu/dept/ncs/newsarch/2005/Feb05/detox.htm

http://www.csmonitor.com/2005/0324/p14s02-sten.html

http://www.sciencedaily.com/releases/2005/02/050223151656.htm

Genetic discussion:

http://www.biology.neu.edu/faculty03/cheney03.html

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