title: Methanotrophic bacteria in oilsands tailings ponds of northern Alberta.
abstract: We investigated methanotrophic bacteria in slightly alkaline surface water (pH 7.4-8.7) of oilsands tailings ponds in Fort McMurray, Canada. These large lakes (up to 10 km(2)) contain water, silt, clay and residual hydrocarbons that are not recovered in oilsands mining. They are primarily anoxic and produce methane but have an aerobic surface layer. Aerobic methane oxidation was measured in the surface water at rates up to 152 nmol CH4 ml(-1) water d(-1). Microbial diversity was investigated via pyrotag sequencing of amplified 16S rRNA genes, as well as by analysis of methanotroph-specific pmoA genes using both pyrosequencing and microarray analysis. The predominantly detected methanotroph in surface waters at all sampling times was an uncultured species related to the gammaproteobacterial genus Methylocaldum, although a few other methanotrophs were also detected, including Methylomonas spp. Active species were identified via (13)CH4 stable isotope probing (SIP) of DNA, combined with pyrotag sequencing and shotgun metagenomic sequencing of heavy (13)C-DNA. The SIP-PCR results demonstrated that the Methylocaldum and Methylomonas spp. actively consumed methane in fresh tailings pond water. Metagenomic analysis of DNA from the heavy SIP fraction verified the PCR-based results and identified additional pmoA genes not detected via PCR. The metagenome indicated that the overall methylotrophic community possessed known pathways for formaldehyde oxidation, carbon fixation and detoxification of nitrogenous compounds but appeared to possess only particulate methane monooxygenase not soluble methane monooxygenase.
authors.affiliation: Department of Biological Sciences, University of Calgary, Calgary, Alberta, Canada.
authors.forename: Alireza
authors.initials: A
authors.lastname: Saidi-Mehrabad
authors.forename: Zhiguo
authors.initials: Z
authors.lastname: He
authors.forename: Ivica
authors.initials: I
authors.lastname: Tamas
authors.forename: Christine E
authors.initials: CE
authors.lastname: Sharp
authors.forename: Allyson L
authors.initials: AL
authors.lastname: Brady
authors.forename: Fauziah F
authors.initials: FF
authors.lastname: Rochman
authors.forename: Levente
authors.initials: L
authors.lastname: Bodrossy
authors.forename: Guy Cj
authors.initials: GC
authors.lastname: Abell
authors.forename: Tara
authors.initials: T
authors.lastname: Penner
authors.forename: Xiaoli
authors.initials: X
authors.lastname: Dong
authors.forename: Christoph W
authors.initials: CW
authors.lastname: Sensen
authors.forename: Peter F
authors.initials: PF
authors.lastname: Dunfield
mesh_terms: D000416:Alberta; D001419:Bacteria / Q000145:classification / Q000235:genetics / Q000378:metabolism*; D004269:DNA, Bacterial / Q000235:genetics; D020563:Gammaproteobacteria / Q000145:classification / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism; D019015:Geologic Sediments / Q000382:microbiology*; D054892:Metagenome; D008697:Methane / Q000378:metabolism; D008772:Methylococcaceae / Q000145:classification / Q000235:genetics / Q000378:metabolism*; D010578:Petroleum / Q000382:microbiology; D010802:Phylogeny; D016133:Polymerase Chain Reaction; D061005:Ponds / Q000382:microbiology*; D012336:RNA, Ribosomal, 16S / Q000235:genetics
chemical_list: D004269:DNA, Bacterial; D010578:Petroleum; D012336:RNA, Ribosomal, 16S; D008697:Methane