Identification of a Novel Toluene-Degrading Bacterium from the Candidate Phylum TM7, as Determined by DNA Stable Isotope Probing

The dominant bacterium responsible for carbon uptake from toluene in an agricultural soil was identified by stable isotope probing. Samples were amended with unlabeled toluene or labeled [ring-(13)C(6)]toluene, and DNA was extracted over time. Sequencing indicated that the organism involved belongs to the candidate phylum TM7. Microorganisms in this candidate phylum are of particular interest because although they have been found in a variety of habitats, no stable culture of any species exists, so their general metabolic capabilities are largely unknown.