title: Environmental, genomic and taxonomic perspectives on methanotrophic Verrucomicrobia.
abstract: Aerobic methanotrophic bacteria are capable of utilizing methane as their sole energy source. They are commonly found at the oxic/anoxic interfaces of environments such as wetlands, aquatic sediments, and landfills, where they feed on methane produced in anoxic zones of these environments. Until recently, all known species of aerobic methanotrophs belonged to the phylum Proteobacteria, in the classes Gammaproteobacteria and Alphaproteobacteria. However, in 2007-2008 three research groups independently described the isolation of thermoacidophilic methanotrophs that represented a distinct lineage within the bacterial phylum Verrucomicrobia. Isolates were obtained from geothermal areas in Italy, New Zealand and Russia. They are by far the most acidophilic methanotrophs known, with a lower growth limit below pH 1. Here we summarize the properties of these novel methanotrophic Verrucomicrobia, compare them with the proteobacterial methanotrophs, propose a unified taxonomic framework for them and speculate on their potential environmental significance. New genomic and physiological data are combined with existing information to allow detailed comparison of the three strains. We propose the new genus Methylacidiphilum to encompass all three newly discovered bacteria.
authors.affiliation: Department of Microbiology, IWWR, Radboud University Nijmegen, Toernooiveld 1, NL-6525 ED Nijmegen, The Netherlands. Department of Biology and Centre for Geobiology, University of Bergen, P.O. Box 7800, N-5020 Bergen, Norway. GNS Science, Extremophile Research Group, Private Bag 2000, 3352 Taupo, New Zealand. Department of Biological Sciences, University of Calgary, 2500 University Drive NW, Calgary, AB, Canada, T2N 1N4. NIOZ Royal Netherlands Institute for Sea Research, Department of Marine Organic Biogeochemistry, P.O. Box 59, 1790 AB Den Burg, Texel, The Netherlands.
authors.forename: Huub J M
authors.initials: HJ
authors.lastname: Op den Camp
authors.forename: Tajul
authors.initials: T
authors.lastname: Islam
authors.forename: Matthew B
authors.initials: MB
authors.lastname: Stott
authors.forename: Harry R
authors.initials: HR
authors.lastname: Harhangi
authors.forename: Alexander
authors.initials: A
authors.lastname: Hynes
authors.forename: Stefan
authors.initials: S
authors.lastname: Schouten
authors.forename: Mike S M
authors.initials: MS
authors.lastname: Jetten
authors.forename: Nils-Kåre
authors.initials: NK
authors.lastname: Birkeland
authors.forename: Arjan
authors.initials: A
authors.lastname: Pol
authors.forename: Peter F
authors.initials: PF
authors.lastname: Dunfield