Featured Research

from universities, journals, and other organizations

Researchers Close In On Natural Solution To PCB Contamination

Date:
November 5, 2002
Source:
Purdue University
Summary:
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.

WEST LAFAYETTE, Ind. -- 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.

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.


Story Source:

The above story is based on materials provided by Purdue University. Note: Materials may be edited for content and length.


Cite This Page:

Purdue University. "Researchers Close In On Natural Solution To PCB Contamination." ScienceDaily. ScienceDaily, 5 November 2002. <www.sciencedaily.com/releases/2002/11/021105080338.htm>.
Purdue University. (2002, November 5). Researchers Close In On Natural Solution To PCB Contamination. ScienceDaily. Retrieved September 19, 2014 from www.sciencedaily.com/releases/2002/11/021105080338.htm
Purdue University. "Researchers Close In On Natural Solution To PCB Contamination." ScienceDaily. www.sciencedaily.com/releases/2002/11/021105080338.htm (accessed September 19, 2014).

Share This



More Plants & Animals News

Friday, September 19, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Raw: Elephant Undergoes Surgery in Tbilisi Zoo

Raw: Elephant Undergoes Surgery in Tbilisi Zoo

AP (Sep. 18, 2014) Grand the elephant has successfully undergone surgery to remove a portion of infected tusk at Tbilisi Zoo in Georgia. British veterinary surgeons used an electric drill to extract the infected piece. (Sept. 18) Video provided by AP
Powered by NewsLook.com
Chimp Violence Study Renews Debate On Why They Kill

Chimp Violence Study Renews Debate On Why They Kill

Newsy (Sep. 17, 2014) The study weighs in on a debate over whether chimps are naturally violent or become that way due to human interference in the environment. Video provided by Newsy
Powered by NewsLook.com
Some Tobacco Farmers Thrive Amid Challenges

Some Tobacco Farmers Thrive Amid Challenges

AP (Sep. 16, 2014) The South's tobacco country is surviving, and even thriving in some cases, as demand overseas keeps growers in the fields of one of America's oldest cash crops. (Sept. 16) Video provided by AP
Powered by NewsLook.com
Scientists Given Rare Glimpse of 350-Kilo Colossal Squid

Scientists Given Rare Glimpse of 350-Kilo Colossal Squid

AFP (Sep. 16, 2014) Scientists say a female colossal squid weighing an estimated 350 kilograms (770 lbs) and thought to be only the second intact specimen ever found was carrying eggs when discovered in the Antarctic. Duration: 00:47 Video provided by AFP
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins