Microbial Ecology of Subsurface Oil Sands Deposits  in Northern Alberta, Canada

Ridley, Christina M.

Microbial Ecology of Subsurface Oil Sands Deposits in Northern Alberta, Canada

dc.contributor.advisor	Gieg, Lisa Marie
dc.contributor.advisor	Voordouw, Gerrit
dc.contributor.author	Ridley, Christina M.
dc.contributor.committeemember	Strous, Marc
dc.contributor.committeemember	Biddle, Jennifer
dc.contributor.committeemember	Hubert, Casey R. J.
dc.date	2018-11
dc.date.accessioned	2018-08-10T20:18:33Z
dc.date.available	2018-08-10T20:18:33Z
dc.date.issued	2018-08-09
dc.description.abstract	The subsurface Athabasca Oil Sands in northern Alberta, Canada, is an important yet understudied microbial habitat. Over geological time, progressive biodegradation of low molecular weight hydrocarbons by indigenous microorganisms has resulted in an enrichment of high molecular weight hydrocarbons known as bitumen. This is an extreme environment characterized by low water and nutrient availability, thereby resulting in low microbial biomass. The objective of this study was to characterize the microbial ecology of this unique ecosystem, which could ultimately provide a basis for the development of microbially enhanced oil recovery (MEOR) technologies. To that end, pristine core samples were collected from 220 to 320 meters below the surface during 3 annual field trips. Due to the high bitumen and low biomass content of the core samples, extensive method development and validation was performed to identify a robust molecular biological workflow that would allow for consistently successful extraction, amplification and sequencing of genomic DNA from core samples. This molecular biological method was then used to characterize the prokaryotic and eukaryotic microbial communities of the subsurface oil sands through 16S and 18S rRNA gene sequencing. Results revealed a surprising predominance of aerobic and facultative microorganisms in an environment that is traditionally considered anoxic. The genera Pseudomonas, Acinetobacter and Fontibacter were the dominant prokaryotes in all core samples (average relative sequence abundance >5%). Methanoculleus was the only methanogen detected at an average relative sequence abundance >1%. Fungi from the family Trichocomaceae and the order Hypocreales were the prevailing Eukaryotes. Core sample incubations were used to determine the effects of atmosphere and temperature on microbial community succession. Microcosms were established under aerobic, microaerobic and anaerobic atmospheres at reservoir (8°C), mesophilic (33°C) and thermophilic (60°C) temperatures. Results indicate that the predominant community members remained similar to the controls; however, some microcosms incubated at 60°C experienced enrichment of thermophiles, including the genera Thermus, Geobacillus and Thermanaerothrix. Many of the dominant taxa observed in this study could have potential MEOR applications, including hydrocarbon degradation, biosurfactant production and methanogenesis. Thus, the information revealed in this study could be used as the basis for MEOR technologies.	en_US
dc.identifier.citation	Ridley, C. M. (2018). Microbial Ecology of Subsurface Oil Sands Deposits in Northern Alberta, Canada (Doctoral thesis, University of Calgary, Calgary, Canada). Retrieved from https://prism.ucalgary.ca. doi:10.11575/PRISM/32803	en_US
dc.identifier.doi	http://dx.doi.org/10.11575/PRISM/32803
dc.identifier.uri	http://hdl.handle.net/1880/107621
dc.language.iso	eng
dc.publisher.faculty	Graduate Studies
dc.publisher.faculty	Science
dc.publisher.institution	University of Calgary	en
dc.publisher.place	Calgary	en
dc.rights	University of Calgary graduate students retain copyright ownership and moral rights for their thesis. You may use this material in any way that is permitted by the Copyright Act or through licensing that has been assigned to the document. For uses that are not allowable under copyright legislation or licensing, you are required to seek permission.
dc.subject	microbial ecology
dc.subject	microbial community analysis
dc.subject	petroleum microbiology
dc.subject	oil sands microbiology
dc.subject	subsurface microbiology
dc.subject	microbially enhanced oil recovery (MEOR)
dc.subject.classification	Biology	en_US
dc.subject.classification	Microbiology	en_US
dc.subject.classification	Biology--Molecular	en_US
dc.subject.classification	Engineering--Environmental	en_US
dc.title	Microbial Ecology of Subsurface Oil Sands Deposits in Northern Alberta, Canada
dc.type	doctoral thesis
thesis.degree.discipline	Biological Sciences
thesis.degree.grantor	University of Calgary
thesis.degree.name	Doctor of Philosophy (PhD)
ucalgary.item.requestcopy	true