( A microbial community thriving under bi...)ORNL, UC Berkeley unravel real-world clues to Earth's mysteries

In a paper to appear today on Science Online, researchers from the Department of Energy's Oak Ridge National Laboratory and the University of California Berkeley describe a bacterial community that flourishes in the iron sulfide-rich runoff of the Richmond Mine near Redding. A pH level of 7 is considered neutral and most proteins prefer pH levels between 5 and 7. The water trickling from the mine has a pH of about 0.8 and a temperature of 107 degrees Fahrenheit.

"This microbial community is thriving at the extreme edge," said Bob Hettich, a co-author and member of ORNL's Chemical Sciences Division. "A pH level of 0.8 is like swimming in sulfuric acid, so we'd like to know how this community can survive and how we might be able to use this information to better understand microbial systems in real-world conditions."

The work is significant on a number of levels, according to the research team, which noted that while microbial communities play key roles in the Earth's bio-geochemical cycles, scientists know little about the structure and activities within these communities. This is because the commonly used artificially cultivated organisms lack the diversity found in nature, so potentially critical community and environmental interactions go unsampled.

Raymond Orbach, director of DOE's Office of Science, noted that this research offers a glimpse of what will be possible in the near future. "This work illustrates the power of the genome sequencing done at the Department of Energy's Joint Genome Institute to contribute to understanding the microbiological communities living at contaminated sites," Orbach said. "Now scientists can investigate not only the 'community genome,' but also the resulting 'comm
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Source:DOE/Oak Ridge National Laboratory