University of Waterloo, Department of Biology
Alyssa Graham is a master's student in Dr. Laura Hug's lab at the University of Waterloo in the Department of Biology. She recently earned her BSc in Biology at the University of Waterloo with a specialization in microbiology and bioinformatics. Alyssa's research interests include bioremediation, water quality and treatment, environmental microbiology, and the application of bioinformatics.
The Impact of 1,4-Dioxane and Trichloroethylene on the Activity and Composition of a Landfill Microbial Community
1,4-dioxane is a probable human carcinogen and emerging groundwater contaminant of concern, with landfills being one of the largest point sources. Remediation is complicated by dioxane’s persistence in the environment and co-occurrence with chlorinated solvents like trichloroethylene (TCE). Bioremediation is one proposed solution to address dioxane contamination; however, known dioxane degraders require oxygen and the majority of impacted groundwater systems are anoxic, rendering degraders ineffective in situ. We investigated anaerobic dioxane degradation potential using enrichment cultures inoculated with landfill leachate. Cultures were amended with dioxane or co-contaminated with TCE across a groundwater redox gradient. While dioxane was not degraded, results suggest landfill microbial community members showed tolerance to high dioxane concentrations while responding to redox conditions. TCE degradation was observed in fermentative cultures, catalyzed by novel Dehalococcoides. This work provides information about microbial dioxane tolerance, TCE degradation in the presence of dioxane, and steps towards anaerobic dioxane degradation tool development.