title: Identification of the functionally active methanotroph population in a peat soil microcosm by stable-isotope probing.
abstract: The active population of low-affinity methanotrophs in a peat soil microcosm was characterized by stable-isotope probing. "Heavy" (13)C-labeled DNA, produced after microbial growth on (13)CH(4), was separated from naturally abundant (12)C-DNA by cesium chloride density gradient centrifugation and used as a template for the PCR. Amplification products of 16S rRNA genes and pmoA, mxaF, and mmoX, which encode key enzymes in the CH(4) oxidation pathway, were analyzed. Sequences related to extant type I and type II methanotrophs were identified, indicating that these methanotrophs were active in peat exposed to 8% (vol/vol) CH(4). The (13)C-DNA libraries also contained clones that were related to beta-subclass Proteobacteria, suggesting that novel groups of bacteria may also be involved in CH(4) cycling in this soil.
authors.affiliation: Department of Biological Sciences, University of Warwick, Coventry CV4 7AL, United Kingdom.
authors.forename: Samantha A
authors.initials: SA
authors.lastname: Morris
authors.forename: Stefan
authors.initials: S
authors.lastname: Radajewski
authors.forename: Toby W
authors.initials: TW
authors.lastname: Willison
authors.forename: J Colin
authors.initials: JC
authors.lastname: Murrell
mesh_terms: D000429:Alcohol Oxidoreductases / Q000235:genetics; D001419:Bacteria / Q000145:classification* / Q000235:genetics / Q000378:metabolism; D002247:Carbon Isotopes / Q000378:metabolism; D002250:Carbon Radioisotopes / Q000378:metabolism; D003001:Cloning, Molecular; D004269:DNA, Bacterial / Q000032:analysis / Q000235:genetics; D017753:Ecosystem; D015723:Gene Library; D020459:Genes, rRNA / Q000235:genetics; D008697:Methane / Q000378:metabolism*; D010105:Oxygenases / Q000235:genetics; D010802:Phylogeny; D016133:Polymerase Chain Reaction; D017422:Sequence Analysis, DNA; D012988:Soil Microbiology
chemical_list: D002247:Carbon Isotopes; D002250:Carbon Radioisotopes; D004269:DNA, Bacterial; D000429:Alcohol Oxidoreductases; C019641:alcohol dehydrogenase (acceptor); D010105:Oxygenases; C021555:methane monooxygenase; D008697:Methane