Small creatures, big jobs: using bacteria to clean up toxic waste

The EU is funding research to learn more about how bacteria and other microorganisms can better survive toxic settings so that they can be used to clean hazardous waste sites. Breakthroughs could help communities clean up abandoned chemical plants, polluted military bases, leaky fuel tanks and other sources of soil and water pollution throughout Europe.

Scientists discovered in the 1970s that certain types of bacteria could be used to clean up toxic waste - literally by consuming and digesting it. However, many types of pollution-eating bacteria that did their jobs in laboratories did not work so well when they were introduced to contaminated sites. They simply starved and died before consuming any of the waste.

Researchers with the EU-funded "BACSIN" project are working to overcome this critical challenge: helping bacteria survive after they are released into highly toxic environments.

"The idea was simple: we could go to a catalogue, pick out a bacteria - A, B, C - apply it to the contaminated area, and then the contaminated area would be gone," said BACSIN coordinator Jan Roelof van der Meer of University of Lausanne in Switzerland. "But this hardly ever works in practice. You can't just spray bacteria on the pollution."

Marking significant progress, van der Meer's team has discovered that plants can be used to protect bacteria after they are placed in toxic settings by giving them a place to live on their roots and providing nutrients. Plant seeds and the roots of saplings are coated with or soaked in the bacteria, which then "grow with" the plants, van der Meer said. After the plants are placed in a toxic site, he said, the plants' roots provide nutrients and protection to the bacteria. Because healthy bacteria multiply spontaneously and on a massive scale, they can digest waste quickly once they begin to thrive.

This technique has been successfully transferred from the lab to the field, offering potential for cleaning up Europe's many remaining toxic sites. It also opens up a huge market for BACSIN's work, van der Meer said, including polluted military installations such as a former Soviet airbase in the Czech Republic, and chemical factories like those in Germany's Leipzig-Bitterfeld area. BACSIN is working through its partners toward performing future clean-up work at these sites.

The very notion of pollution-eating bacteria is a quirk of nature. Ironically, many toxins are ideal food for certain bacteria. The bacteria that are used to clean up oil spills, for instance, evolved this way because of natural oil seeps from the ocean bottom. A bacteria discovered in the Antarctic Ocean can break down diesel oil and PCBs. Other bacteria can remove chlorine from carcinogenic solvents and dry-cleaning chemicals.

Past discoveries such as these, combined with the progress already achieved by BACSIN, is cause for hope. "Our work has produced some very stimulating findings," van der Meer said, referring to the discovery that these bacteria's can live in toxic areas when supported by plants. "I'm very optimistic" states van der Meer.

Emily Jones e.jones@media-consulta.com
Media consultant