Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

UGA researchers use transgenic trees to help clean up toxic waste site

11.09.2003


Can genetically engineered cottonwood trees clean up a site contaminated with toxic mercury? A team of researchers from the University of Georgia - in the first such field test ever done with trees - is about to find out.



The results could make clearer the future of phytoremediation - a technique of using trees, grasses and other plants to remove hazardous materials from the soil. UGA scientists and city officials in Danbury, Conn., planted on July 16 some 60 cottonwoods with a special gene at the site of a 19th-century hat factory in that northeastern city.

"We hope to see a significant difference in the levels of mercury in the soil within 18 months, perhaps as much as a twofold reduction," said Richard Meagher, professor of genetics at UGA.


The field test is a collaboration between UGA, Western Connecticut State University, Applied PhytoGenetics, Inc., of Athens and the City of Danbury.

While the technology now being used in Danbury does not apply to all sites, mercury pollution is a pervasive problem in Georgia as it is elsewhere. The site of a former chemical factory near Brunswick, for example, is polluted with mercury and other toxic chemicals. Mercury contamination has been reported around the sites of former gold mines in north Georgia, and advisories have been issued during the past decade for mercury-contaminated fish in more than 80 streams, lakes and creeks in the state.

Meagher’s team did the first-ever field trial of a genetically engineered plant to sequester mercury when it grew transgenic tobacco in a New Jersey field trial in 2001, but this is the first such trial using trees, whose larger root systems and year-round life cycle makes them better candidates for long-term cleaning of polluted soil.

Phytoremediation is a relatively new field and one gaining international interest. A team of photographers working for National Geographic, for instance, recently spent considerable time with Meagher capturing on film his work as part of a four-part documentary that will be aired some time next winter.

Meagher has for more than a decade been a pioneer in phytoremediation, and he was the first to demonstrate that a gene called merA can be inserted into plants and used to detoxify mercury in the environment. While no plant can break mercury down, since it is an element, less toxic forms can be created, and that has been the goal of Meagher’s lab - to find ways to let plants or trees grow on polluted sites, draw such heavy metals as mercury into the plants themselves and then either transpire the much less toxic forms of the metal into the air where they are quickly diffused or trap the metal aboveground for later harvest.

The project with Danbury came about because Danbury’s environmental coordinator, Jack Kozuchowski, had in 1977 published an early study that showed how native plants could transfer mercury from contaminated soils into the atmosphere. Kozuchowski, aware of Meagher’s work, convinced officials in Danbury that the so-called Barnum Court site in that town would be a perfect site for a field trial of the genetically engineered trees that Meagher and his collaborator Scott Merkle developed.

The city was awarded a grant of some $55,162 from the Environmental Protection Agency to explore use of the technology, and the trial was set up - though most costs for the work are being born by those involved in it.

"It is our hope that the research will lead to a cleansing of the Barnum Court property so the city can transfer the property for development," said Mark Boughton, mayor of Danbury.

Meagher’s mercury phytoremediation technology is exclusively licensed to Applied PhytoGenetics, or APGEN as it is called, and that Athens company has been instrumental in helping set up the field trial. (Meagher is a consultant to and cofounder of APGEN.)

Postdoctoral associate Andrew Heaton of Meagher’s lab and one other of Meagher’s students traveled to Danbury in July to supervise planting the genetically engineered trees on the site in enclosed plastic containers buried on the site.

Because the mercury on the site ranges, depending on location, from five to more than 300 parts per million, trials were set up to measure the effects of the cottonwood trees on progressively more polluted samples of soil. Forty-five plots, most planted with four trees each, are located on the site, which is in a mixed-use urban area and whose total area is less than an acre. (Some 15 plots have four merA trees, 15 are nonengineered or "wild-type" trees and 15 received no trees at all, so there are 120 trees in the field test.)

The form of mercury at the Danbury site is ionic mercury, a species that can be sequestered and transformed into less toxic metallic mercury in the transgenic trees and then transpired into the atmosphere. (Several forms of mercury were used in hat-making in the 19th century, but their toxic effects often sickened workers and led to the phrase "mad hatter," which described the process of neurological degeneration that came from working with the metal. In this part of New England, the symptoms of mercury poisoning were called the "Danbury shakes.")

Meagher’s lab actually has two genes that can effect phytoremediation, merA and merB, but since the merA is active on ionic mercury, the cottonwoods trees chosen for the Danbury trial express the merA gene.

"This is a field test, not a cleanup," said Meagher. "And we will be measuring mercury in both the soil and the trees to see just how much success we have in reducing the mercury levels in the soil. We are very optimistic that this technology will work."

While the trees at the site will have to be watered, the costs of that pale in comparison to traditional clean-up methods - digging up the polluted soil and hauling it off for storage at another site, possibly greater than $1 million.

A team of researchers from Western Connecticut State University will be studying the role of soil microorganisms in the potential clean-up of mercury on the site. According to the City of Danbury, the field test will run through the 2004 growing season, and if results are positive, genetically engineered cottonwood trees will be used to clean the whole site.

Kim Carlyle | EurekAlert!
Further information:
http://www.uga.edu/

More articles from Ecology, The Environment and Conservation:

nachricht Upcycling 'fast fashion' to reduce waste and pollution
03.04.2017 | American Chemical Society

nachricht Litter is present throughout the world’s oceans: 1,220 species affected
27.03.2017 | Alfred-Wegener-Institut, Helmholtz-Zentrum für Polar- und Meeresforschung

All articles from Ecology, The Environment and Conservation >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Making lightweight construction suitable for series production

More and more automobile companies are focusing on body parts made of carbon fiber reinforced plastics (CFRP). However, manufacturing and repair costs must be further reduced in order to make CFRP more economical in use. Together with the Volkswagen AG and five other partners in the project HolQueSt 3D, the Laser Zentrum Hannover e.V. (LZH) has developed laser processes for the automatic trimming, drilling and repair of three-dimensional components.

Automated manufacturing processes are the basis for ultimately establishing the series production of CFRP components. In the project HolQueSt 3D, the LZH has...

Im Focus: Wonder material? Novel nanotube structure strengthens thin films for flexible electronics

Reflecting the structure of composites found in nature and the ancient world, researchers at the University of Illinois at Urbana-Champaign have synthesized thin carbon nanotube (CNT) textiles that exhibit both high electrical conductivity and a level of toughness that is about fifty times higher than copper films, currently used in electronics.

"The structural robustness of thin metal films has significant importance for the reliable operation of smart skin and flexible electronics including...

Im Focus: Deep inside Galaxy M87

The nearby, giant radio galaxy M87 hosts a supermassive black hole (BH) and is well-known for its bright jet dominating the spectrum over ten orders of magnitude in frequency. Due to its proximity, jet prominence, and the large black hole mass, M87 is the best laboratory for investigating the formation, acceleration, and collimation of relativistic jets. A research team led by Silke Britzen from the Max Planck Institute for Radio Astronomy in Bonn, Germany, has found strong indication for turbulent processes connecting the accretion disk and the jet of that galaxy providing insights into the longstanding problem of the origin of astrophysical jets.

Supermassive black holes form some of the most enigmatic phenomena in astrophysics. Their enormous energy output is supposed to be generated by the...

Im Focus: A Quantum Low Pass for Photons

Physicists in Garching observe novel quantum effect that limits the number of emitted photons.

The probability to find a certain number of photons inside a laser pulse usually corresponds to a classical distribution of independent events, the so-called...

Im Focus: Microprocessors based on a layer of just three atoms

Microprocessors based on atomically thin materials hold the promise of the evolution of traditional processors as well as new applications in the field of flexible electronics. Now, a TU Wien research team led by Thomas Müller has made a breakthrough in this field as part of an ongoing research project.

Two-dimensional materials, or 2D materials for short, are extremely versatile, although – or often more precisely because – they are made up of just one or a...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Fighting drug resistant tuberculosis – InfectoGnostics meets MYCO-NET² partners in Peru

28.04.2017 | Event News

Expert meeting “Health Business Connect” will connect international medical technology companies

20.04.2017 | Event News

Wenn der Computer das Gehirn austrickst

18.04.2017 | Event News

 
Latest News

Wireless power can drive tiny electronic devices in the GI tract

28.04.2017 | Medical Engineering

Ice cave in Transylvania yields window into region's past

28.04.2017 | Earth Sciences

Nose2Brain – Better Therapy for Multiple Sclerosis

28.04.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>