Although naphthalene is not the most toxic component in coal tar, the microbiologists say their discovery might eventually help to speed the cleanup of hundreds of 19th and 20th century gasworks throughout the United States where the manufacture of gas from coal for homes and street lighting left a toxic legacy in the ground.
The National Science Foundation-funded research is reported in the online edition of Proceedings of the National Academy of Sciences (PNAS early edition, Oct. 27, 2003) by researchers working at the NSF Microbial Observatory at Cornell.
The naphthalene-eating bacterium, Polaromonas naphthalenivorans strain CJ2, was discovered in a 40-year-old municipal gasworks coal tar disposal site in South Glens Falls, N.Y., near the west bank of the Hudson River.
"Strain CJ2 alone won't solve the coal tar problem because naphthalene is only one of the many organic chemicals involved. That's why we're going back to look for other microorganisms -- perhaps with similar gene sequences -- that might be biodegrading other toxins," says the article's lead author, Eugene L. Madsen, associate professor of microbiology in Cornell's College of Agriculture and Life Sciences. He says that naphthalene's carcinogenic relatives in coal tar, known as polycylic aromatic hydrocarbons, are toxins that his research group hopes to degrade.
The use of SIP to identify pollutant-eating microbes is something like using the milk-mustache test to discover which child drank the milk. In the first successful field application of SIP in a contaminated site, the microbiologists released into the Hudson River
Contact: Roger Segelken
Cornell University News Service