Investigating thermophilic methanotrophs in a Manitoba landfill biowindow
| dc.contributor.author | Plouffe, Jocelyn | |
| dc.contributor.examiningcommittee | Uyaguari-Diaz, Miguel (Microbiology) | en_US |
| dc.contributor.examiningcommittee | Yuan, Qiuyan (Civil Engineering) | en_US |
| dc.contributor.supervisor | Sparling, Richard | |
| dc.date.accessioned | 2023-03-28T15:01:09Z | |
| dc.date.available | 2023-03-28T15:01:09Z | |
| dc.date.copyright | 2023-03-25 | |
| dc.date.issued | 2023-03-25 | |
| dc.date.submitted | 2023-03-25T22:29:14Z | en_US |
| dc.degree.discipline | Microbiology | en_US |
| dc.degree.level | Master of Science (M.Sc.) | en_US |
| dc.description.abstract | In Canada, landfills are responsible for 23% of all emissions of methane, a greenhouse gas with 28x the potency of carbon dioxide. Gas collection systems can be used to mitigate landfill emissions but are not feasible for many municipal solid waste facilities. This has led to the increased importance of exploring innovative biocover solutions which incorporate on-site compost materials to enhance methane mitigation by microorganisms known as methanotrophs. This thesis examines the microbial community of biowindow soil alongside conventional landfill cover soil and on-site compost windrows, with a focus on aerobic methanotrophic bacteria. Initial methane-oxidation potential of the different soil types were measured throughout various seasonal conditions, revealing high activity in the spring but substantially decreased levels of methane-oxidation throughout drought-like conditions in the summer of 2021 and through into late fall. 16S rRNA analysis and amplicon sequencing of the methanotroph marker gene pmoA in soil detected high proportions of methanotrophs, with a particular abundance of cyst-forming Methylocystis and thermophilic Methylocaldum. Amplicon sequencing of pmoA using methanotroph enrichment culture DNA identified a large proportion of unclassified organisms at the genus level, and phylogenetic analysis strongly suggested these uncultured bacteria belong to Methylocaldum. Enrichment cultures using soil inocula found despite low initial oxidation potential methanotrophs responded positively given the optimum conditions, indicating their resilience to desiccation and large temperature fluctuations occurring in situ. Attempted isolation of thermophilic methanotrophs resulted in the identification of Meiothermus silvanus via whole genome sequencing, the first documentation of this organism in a landfill and the first known record of a thermophilic organism being isolated from a continental climate landfill. M. silvanus belongs to a genus of heterotrophic thermophiles previously suggested to display synergistic relationships with Methylosinus, a methanotroph that was also detected in this landfill through amplicon sequencing. This study demonstrated that even in a climate facing weather extremes exceeding -30C to +30C, thermophilic methanotrophs persist throughout the seasons and presumably play a substantial role in methane oxidation within the biowindow. The research performed in this thesis helps to increase our understanding of landfill biotic systems and their application in a continental climate. | en_US |
| dc.description.note | May 2023 | en_US |
| dc.identifier.uri | http://hdl.handle.net/1993/37223 | |
| dc.language.iso | eng | en_US |
| dc.rights | open access | en_US |
| dc.subject | methanotroph | en_US |
| dc.subject | methane | en_US |
| dc.subject | methane-oxidation | en_US |
| dc.subject | greenhouse gas | en_US |
| dc.subject | landfill | en_US |
| dc.title | Investigating thermophilic methanotrophs in a Manitoba landfill biowindow | en_US |
| dc.type | master thesis | en_US |
| local.subject.manitoba | yes | en_US |
| oaire.awardTitle | Robert P. Stearn/SCS Engineers Scholarship | en_US |
| oaire.awardURI | https://erefdn.org/scholarship-program/ | en_US |
| project.funder.identifier | http://dx.doi.org/10.13039/100001604 | en_US |
| project.funder.name | Environmental Research and Education Foundation | en_US |