Project name: uncultured bacterium

Description: We have investigated methanotrophic bacteria in alkaline surface water (pH 7.5-8.8)of oilsands tailings ponds in Fort McMurray, Canada. These large lakes (up to 10km2) contain silt, clay, processing chemicals, and residual hydrocarbons, which werenot recovered in oilsands mining. They are strongly methanogenic, but have anaerobic surface layer. Aerobic methane oxidation was measured in the surface waterat rates up to 200 nmol CH4 ml-1 water d-1. Microbial diversity was investigated viapyrotag sequencing of amplified 16S rRNA genes as well as by analysis ofmethanotroph-specific pmoA genes using both pyrosequencing and microarray analysis.The predominantly detected methanotroph in all tailings ponds at all sampling timeswas an uncultured species related to the gammaproteobacterium Methylocaldum,although a few other methanotrophs were also detected, including Methylomonas.Active species were identified via 13CH4 stable isotope probing (SIP) of DNA,combined with pyrotag sequencing and complete shotgun metagenomic sequencing ofheavy 13C-DNA. The SIP results demonstrated that the Methylocaldum and Methylomonasstrains actively consumed methane in fresh tailings. Metagenomic analysis of DNAfrom the heavy SIP fraction verified the PCR-based results and identified additionalpmoA genes not detected via PCR. The metagenome indicated that the overallmethylotrophic community possessed known pathways for formaldehyde oxidation, carbonfixation, and detoxification of nitrogenous compounds, but appeared to possess onlyparticulate methane monooxygenase, not soluble methane monooxygenase.

Data type: targeted loci

Sample scope: Environment

Relevance: Environmental

Last updated: 2012-06-27