The project is part of the DOE JGI's Community Sequencing Program (CSP: http://www.jgi.doe.gov/CSP/index.html) established in 2004 to take on large-scale genomics efforts in support of DOE mission areas, including characterizing the biological and environmental processes involved in carbon cycling.
Hallam described SUP05 as a paradoxical organism. "Based on genomic analysis and field observations, it provides important ecosystem services but it also produces byproducts that may have negative consequences with respect to climate change," he said. "Specifically, SUP05 removes toxic sulfides from the water, and fixes carbon dioxide but we also think it's producing nitrous oxide, which is a more potent greenhouse gas than either carbon dioxide or methane."
The researchers found that SUP05 is closely related to sulfur-eating gill symbionts of deep sea clams and mussels although unlike them, it utilizes nitrate rather than oxygen in its energy metabolism. A comparative analysis of SUP05 and symbiont genomes also revealed that 35 percent of the SUP05 genome is unique, involved in helping the bacteria adapt to changing environmental conditions such as the seasonal increase and decrease of oxygen levels in Saanich Inlet, and the shifting balance of the nitrate and sulfide levels that are its key energy resources.
"As habitat range expands due to global warming, blooming SUP05 populations have the potential to help offset rising carbon dioxide levels that ultimately lead to ocean acidification," Hallam said. He added that SUP05 and its relat
|Contact: David Gilbert|
DOE/Joint Genome Institute