Denitrification, or breaking down nitrates in soil, is important. It removes the chemicals from potentially contaminating groundwater, but it can also release nitrous oxide, a greenhouse gas, into the atmosphere. Scientists discovered that many species of the low-pH dwelling bacteria in the Rhodanobactergenus are capable of denitrification. This is on the heels of the discovery of Rhodanobacterdenitrificans, a denitrifying bacteria that was found in uranium- and nitrate-contaminated soil at the U.S. DOE Oak Ridge Integrated Field Research Center. It was sequenced as part of a 2010 Community Sequencing Program project at the DOE Joint Genome Institute. The findings inspired scientists to sequence the genomes of other species of the bacteria.
Rethinking Rhodanobacter
An international team of researchers, including those from the DOE JGI, published the results in the August 2012 issue of Journal of Bacteriology. They found three species of the genus Rhodanobacter possessed enzymes that denitrify the soil. Three more had all of the genes for denitrification except for nitrate reduction, which other members of the microbial community may provide. Researchers suggest that the role of Rhodanobacterin the environment should be reevaluated.