Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:


Researchers close in on natural solution to PCB contamination


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,

Sources: Jeffrey Bolin, (765) 494-4922,

Lindsay Eltis, (604) 822-0042,

Purdue News Service: (765) 494-2096;

Chad Boutin | Purdue News
Further information:

More articles from Ecology, The Environment and Conservation:

nachricht Invasive Insects Cost the World Billions Per Year
04.10.2016 | University of Adelaide

nachricht Malaysia's unique freshwater mussels in danger
27.09.2016 | The University of Nottingham Malaysia Campus

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: New 3-D wiring technique brings scalable quantum computers closer to reality

Researchers from the Institute for Quantum Computing (IQC) at the University of Waterloo led the development of a new extensible wiring technique capable of controlling superconducting quantum bits, representing a significant step towards to the realization of a scalable quantum computer.

"The quantum socket is a wiring method that uses three-dimensional wires based on spring-loaded pins to address individual qubits," said Jeremy Béjanin, a PhD...

Im Focus: Scientists develop a semiconductor nanocomposite material that moves in response to light

In a paper in Scientific Reports, a research team at Worcester Polytechnic Institute describes a novel light-activated phenomenon that could become the basis for applications as diverse as microscopic robotic grippers and more efficient solar cells.

A research team at Worcester Polytechnic Institute (WPI) has developed a revolutionary, light-activated semiconductor nanocomposite material that can be used...

Im Focus: Diamonds aren't forever: Sandia, Harvard team create first quantum computer bridge

By forcefully embedding two silicon atoms in a diamond matrix, Sandia researchers have demonstrated for the first time on a single chip all the components needed to create a quantum bridge to link quantum computers together.

"People have already built small quantum computers," says Sandia researcher Ryan Camacho. "Maybe the first useful one won't be a single giant quantum computer...

Im Focus: New Products - Highlights of COMPAMED 2016

COMPAMED has become the leading international marketplace for suppliers of medical manufacturing. The trade fair, which takes place every November and is co-located to MEDICA in Dusseldorf, has been steadily growing over the past years and shows that medical technology remains a rapidly growing market.

In 2016, the joint pavilion by the IVAM Microtechnology Network, the Product Market “High-tech for Medical Devices”, will be located in Hall 8a again and will...

Im Focus: Ultra-thin ferroelectric material for next-generation electronics

'Ferroelectric' materials can switch between different states of electrical polarization in response to an external electric field. This flexibility means they show promise for many applications, for example in electronic devices and computer memory. Current ferroelectric materials are highly valued for their thermal and chemical stability and rapid electro-mechanical responses, but creating a material that is scalable down to the tiny sizes needed for technologies like silicon-based semiconductors (Si-based CMOS) has proven challenging.

Now, Hiroshi Funakubo and co-workers at the Tokyo Institute of Technology, in collaboration with researchers across Japan, have conducted experiments to...

All Focus news of the innovation-report >>>



Event News

#IC2S2: When Social Science meets Computer Science - GESIS will host the IC2S2 conference 2017

14.10.2016 | Event News

Agricultural Trade Developments and Potentials in Central Asia and the South Caucasus

14.10.2016 | Event News

World Health Summit – Day Three: A Call to Action

12.10.2016 | Event News

Latest News

Resolving the mystery of preeclampsia

21.10.2016 | Health and Medicine

Stanford researchers create new special-purpose computer that may someday save us billions

21.10.2016 | Information Technology

From ancient fossils to future cars

21.10.2016 | Materials Sciences

More VideoLinks >>>