Investigating the Microbial Degradation Potential in Oil Sands Fluid Fine Tailings Using Gamma Irradiation: A Metagenomic Perspective

Abstract

Open-pit mining of the Athabasca oil sands has generated large volumes of waste termed fluid fine tailings (FFT), stored in tailings ponds. Accumulation of toxic organic substances in the tailings ponds is one of the biggest concerns. Gamma irradiation (GI) treatment could accelerate the biodegradation of toxic organic substances. Hence, this research investigates the response of the microbial consortia in GI-treated FFT materials with an emphasis on changes in diversity and organism-related stimuli. FFT materials from aged and fresh ponds were used in the study under aerobic and anaerobic conditions. Variations in the microbial diversity in GI-treated FFT materials were monitored for 52 weeks and significant stimuli (p < 0.05) were observed. Chemoorganotrophic organisms dominated in fresh and aged ponds and showed increased relative abundance resulting from GI treatment. GI-treated anaerobic FFT reported stimulus of organisms with biodegradation potential (e.g., Pseudomonas, Enterobacter) and methylotrophic capabilities (e.g., Syntrophus, Smithella). In comparison, GI-treated anaerobic FFT stimulated Desulfuromonas as the principle genus at 52 weeks. Under aerobic conditions, GI-treated FFT showed stimulation of organisms capable of sulfur and iron cycling (e.g., Geobacter). However, GI-treated aerobic FFT showed no stimulus at 52 weeks. This research provides an enhanced understanding of oil sands tailings biogeochemistry and the impacts of GI treatment on microorganisms as an effect for targeting toxic organics. The outcomes of this study highlight the potential for this approach to accelerate stabilization and reclamation end points. Graphical Abstract.

Exploring bacterial pathogen community dynamics in freshwater beach sediments: A tale of two lakes

“…Sediment DNA extractions were performed using PowerSoil Total DNA Isolation kits (MoBio) following the manufacturer's instructions. DNA libraries were developed using a two-stage PCR approach and amplicon product purification was accomplished with SPRI beads (details in the Supporting Information; Vo and Jedlicka, 2014;VanMensel et al, 2017).…”

Petroleum hydrocarbon rich oil refinery sludge of North-East India harbours anaerobic, fermentative, sulfate-reducing, syntrophic and methanogenic microbial populations

“…Ghosal et al, [ 18 ] have reported archaea as one of the six key members with hydrocarbon metabolizing properties along with Alphaproteobacteria , Betaproteobacteria , Gammaproteobacteria , Actinomycetes and Firmicutes . Many members of Deltaproteobacteria are known to be involved in anaerobic hydrocarbon degradation and their abundance often increased with petroleum hydrocarbon contamination [ 27 , 31 ]. In recent years, high throughput sequencing technologies revealed the presence and the importance of less abundant rare microbial groups for maintaining ecosystem functions in diverse habitats.…”

“…Extensive research has elucidated microbial communities from a variety of hydrocarbon contaminated environments including deep water horizon spill, oil contaminated soil or sediments, drill cuttings, production and injection water, etc. [ 3 , 19 – 23 , 26 , 27 , 37 , 39 , 40 ]. However, investigation on petroleum refinery waste sludge microbiome remained little explored.…”