RIVERSIDE, Calif. Environmental scientists at UC Riverside have discovered that the Rancho La Brea tar pits in Los Angeles, Calif., house hundreds of new species of bacteria with unusual properties, allowing the bacteria to survive and grow in heavy oil and natural asphalt.
Trapped in soil that was mixed with heavy oil nearly 28,000 years ago, the bacteria are uniquely adapted to the pits' oil and natural asphalt, and contain three previously undiscovered classes of enzymes that can naturally break down petroleum products, the researchers report.
"We were surprised to find these bacteria because asphalt is an extreme and hostile environment for life to survive," said Jong-Shik Kim, a postdoctoral researcher in the Department of Environmental Sciences, who initiated the study. "It's clear, however, that these living organisms can survive in heavy oil mixtures containing many highly toxic chemicals. Moreover, these bacteria survive with no water and little or no oxygen."
The bacteria and their enzymes have potential application for bioremediation (cleaning oil spills), medical treatments (new medicines), alternative energy (biofuels), enhanced oil recovery, and industrial applications (biochemicals and biotechnology).
Study results appear online in the April 6 issue of Applied and Environmental Microbiology.
Kim and his advisor, David E. Crowley, a professor of environmental microbiology, used DNA-based methods to identify the new bacteria as well as the DNA encoding the three classes of petroleum-degrading enzymes.
"Previously, some bacteria had been cultured from the asphalt, but no one had been able to extract DNA from the asphalt to study the entire microbial community," said Kim, the first author of the paper.