Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Researchers close in on natural solution to PCB contamination

05.11.2002


An environmentally friendly solution to one of the world’s most notorious chemical contamination problems may be a step closer to reality, reports a research team from Purdue University and the University of British Columbia.


A micrograph image of Rhodococcus sp. RHA1, which are good PCB-degraders. Researchers Jeffrey Bolin and Lindsay Eltis hope bacteria, such as these, can be bred to digest PCBs effectively enough to cleanse the environment of these hazardous chemicals. (Photo/UBC Bioimaging Facility)



The team has identified one of the key stumbling blocks that prevent microorganisms from decomposing PCBs (polychlorinated biphenyls), a persistent and potentially hazardous industrial chemical that has become nearly ubiquitous in the environment. While capitalizing on the discovery will take time, it could eventually show researchers how to teach microorganisms to break down PCBs into ecologically safe molecules, a process known as bioremediation.

"We have isolated one of the major hurdles to cleaning up PCBs naturally," said Jeffrey T. Bolin, professor of biological sciences and a member of Purdue’s Markey Center for Structural Biology and Cancer Center. "This gives us a clear picture of one route to degrading PCBs in the environment."


The research appears on the press Web site of Nature Structural Biology.

PCBs were manufactured and used widely in industry for decades, but the 1960s and 1970s brought increased awareness of their toxicity to animals and mass poisonings linked to PCB-contaminated food. PCBs are no longer manufactured in the United States, but their persistence makes them a worldwide problem because many suggested cleanup methods, such as incineration, are ineffective, sometimes even generating other toxic compounds such as dioxins.

"The globe’s entire surface is now contaminated with PCBs," Bolin said. "They are in the soil you walk on and in Arctic ice. They accumulate in organisms as you go up the food chain, especially in aquatic environments, which means that creatures that eat fish – like humans – are particularly likely to absorb large quantities."

Many harmful chemicals in the environment are broken down into benign substances naturally by microorganisms, but PCBs have persisted for decades because decomposers, such as bacteria and fungi, do not find them tasty – at least, not tasty enough.

"PCB molecules actually look very similar to many organic molecules that certain bacteria eat," Bolin said. "But there are enough little differences that bacteria can’t quite digest them. It’s frustrating, because if bacteria could fully digest PCBs, it might solve a worldwide pollution problem. We asked ourselves: What could we do to improve bacterial digestion of PCBs?"

To answer the question, the group has adopted a twofold strategy: first, identify what aspect of PCB breakdown the bacteria are having trouble accomplishing, then breed bacteria to improve their talent at accomplishing it. Bolin said the group’s findings are a breakthrough for the first aspect.

"The process of digestion requires a long chain of chemical steps, and if the bacteria can’t accomplish one of those steps, the chain is broken and digestion can’t occur," Bolin said. "What we have done is isolate one of the steps that causes problems for the bacteria, a clog in the biochemical pipeline if you will."

Now that the group has perspective on this first aspect of the problem, they can focus on improving bacteria for battle against the PCB enemy. Bolin and his research partner, Lindsay Eltis, predict that microorganisms can learn to consume PCBs if properly bred.

"A species will fit itself to a new environment, given many generations to adapt," said Eltis, associate professor of microbiology and biochemistry at the University of British Columbia. "In the case of bacteria, you can get new generations once every few minutes under proper laboratory conditions – just like breeding dogs, only much more rapidly. We hope to use certain species of bacteria with a slight taste for PCBs and improve this trait through breeding until it’s strong enough to make them consume PCBs as a food source."

If the group succeeds, it could mean that PCBs’ days are numbered in the environment. But Eltis emphasizes that there remain difficulties ahead.

"We still have a great deal to do, and it will not be a simple matter to fit a species of bacteria to the task," he said. "But the potential environmental rewards are inspiring. If we succeed, we could get the planet back to where it was before PCBs were ever manufactured."

This research has been funded by the National Institutes of Health and Canada’s National Science and Research Council.

Writer: Chad Boutin, (765) 494-2081, cboutin@purdue.edu

Sources: Jeffrey Bolin, (765) 494-4922, jtb@purdue.edu

Lindsay Eltis, (604) 822-0042, leltis@interchange.ubc.ca

Purdue News Service: (765) 494-2096; purduenews@purdue.edu

Chad Boutin | Purdue News
Further information:
http://press.nature.com/

More articles from Ecology, The Environment and Conservation:

nachricht Bioinvasion on the rise
15.02.2017 | Universität Konstanz

nachricht Litter Levels in the Depths of the Arctic are On the Rise
10.02.2017 | 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: Breakthrough with a chain of gold atoms

In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport

In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport

Im Focus: DNA repair: a new letter in the cell alphabet

Results reveal how discoveries may be hidden in scientific “blind spots”

Cells need to repair damaged DNA in our genes to prevent the development of cancer and other diseases. Our cells therefore activate and send “repair-proteins”...

Im Focus: Dresdner scientists print tomorrow’s world

The Fraunhofer IWS Dresden and Technische Universität Dresden inaugurated their jointly operated Center for Additive Manufacturing Dresden (AMCD) with a festive ceremony on February 7, 2017. Scientists from various disciplines perform research on materials, additive manufacturing processes and innovative technologies, which build up components in a layer by layer process. This technology opens up new horizons for component design and combinations of functions. For example during fabrication, electrical conductors and sensors are already able to be additively manufactured into components. They provide information about stress conditions of a product during operation.

The 3D-printing technology, or additive manufacturing as it is often called, has long made the step out of scientific research laboratories into industrial...

Im Focus: Mimicking nature's cellular architectures via 3-D printing

Research offers new level of control over the structure of 3-D printed materials

Nature does amazing things with limited design materials. Grass, for example, can support its own weight, resist strong wind loads, and recover after being...

Im Focus: Three Magnetic States for Each Hole

Nanometer-scale magnetic perforated grids could create new possibilities for computing. Together with international colleagues, scientists from the Helmholtz Zentrum Dresden-Rossendorf (HZDR) have shown how a cobalt grid can be reliably programmed at room temperature. In addition they discovered that for every hole ("antidot") three magnetic states can be configured. The results have been published in the journal "Scientific Reports".

Physicist Dr. Rantej Bali from the HZDR, together with scientists from Singapore and Australia, designed a special grid structure in a thin layer of cobalt in...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Booth and panel discussion – The Lindau Nobel Laureate Meetings at the AAAS 2017 Annual Meeting

13.02.2017 | Event News

Complex Loading versus Hidden Reserves

10.02.2017 | Event News

International Conference on Crystal Growth in Freiburg

09.02.2017 | Event News

 
Latest News

Impacts of mass coral die-off on Indian Ocean reefs revealed

21.02.2017 | Earth Sciences

Novel breast tomosynthesis technique reduces screening recall rate

21.02.2017 | Medical Engineering

Use your Voice – and Smart Homes will “LISTEN”

21.02.2017 | Trade Fair News

VideoLinks
B2B-VideoLinks
More VideoLinks >>>