Time-dependent variation in the anaerobic microbial community structure of an Alberta Oil Sands Tailings Pond as determined by 16S pyrosequencing
Time-dependent variation in the anaerobic microbial community structure of an Alberta Oil Sands Tailings Pond as determined by 16S pyrosequencing
In the current study, we evaluated the effect of anaerobic storage (90% N2, 10% CO2) on the microbial population from this same active tailings pond. DNA was isolated from selected depths from tailings samples stored under anaerobic conditions for 1.5 years. Analysis of 16S genes by pyrosequencing indicated an increase in fermentative bacteria capable of reducing nitrate (Delftia, Acidovorax, Thauera, Pseudomonas) at most of the depths along with a high abundance of methanogens (Methanosaeta, Methanobacterium, Methanolobus) at a depth of 18 m below the surface. No syntrophs or SRB were detected. UniFrac clustering analysis indicated this community profile to be similar to that of another tailings pond that no longer receives input of fresh tailings. The results indicate that tailings pond microbial communities are dynamic and change rapidly when input of fresh tailings and/or gypsum are stopped. This research was supported by funding from Genome Canada, Genome Alberta, the Government of Alberta and Genome BC.
The microbial diversity in tailings pond hydrocarbon- and long-chain fatty acid degrading population was assessed using a barcoded 16S amplicon approach. Sample preparation with tailings pond samples were performed using sodium pyrophosphate buffer in certain samples to isolated large-sclae of DNA. DNA was isolated either using FastDNA Soil kit or Marmur's method without bead-beating. Little is known about the syntrophic organisms that initially attack hydrocarbons under methanogenic conditions, so this assessment will identify the key microbial players involved in methanogenic decomposition of hydrocarbons and related hydrocarbon compounds.