Adventures in anaerobic bioremediation

Professor, Department of Chemical Engineering and Applied Chemistry and Department of Cell and Systems Biology, University of Toronto

Groundwater contamination is a serious threat to global health and prosperity.  Petroleum hydrocarbons, industrial solvents, pesticides, herbicides, and metals are some of the most frequent culprits.  Some microbes have evolved and adapted to transform or detoxify contaminants.  Certain species, such as Dehalococcoides, can dechlorinate the major dry-cleaning solvent tetrachloroethene and the common industrial solvent trichloroethene to the benign product ethene.  Remarkably, these organisms obtain energy for growth from dechlorination, and several successful demonstrations of bioaugmentation, where an aquifer is inoculated with a mixed microbial culture, have led to the development of a viable commercial market for such dechlorinating cultures.  By studying enrichment cultures and their megagenomes, we are learning more about novel interspecies interactions in these remarkable, ubiquitous, anaerobic microbial communities, and their specialized enzymes that catalyze reductive dehalogenation reactions.  Benzene is another problematic contaminant, readily degraded under oxic conditions, but highly persistent in anaerobic environments.  The anaerobic metabolism of benzene is complex and still largely unknown, yet clues are emerging that reveal novel microbes, pathways and enzymes that could be harnessed for cleanup.  Prospects for biodegradation of other contaminants, including the pesticide chlordecone and perfluorinated substances will be discussed.

Professor Elizabeth Edwards holds Bachelor's and Master's degrees in Chemical Engineering from McGill University, Montreal, and a PhD degree (1993) in Civil and Environmental Engineering from Stanford University.  She is known for her work on anaerobic bioremediation, the application of molecular biology and metagenomics to uncover novel microbial processes, and the transition of laboratory research into commercial practice to develop bioremediation and bioaugmentation strategies for groundwater pollutants. Professor Edwards' research team discovered and characterized novel microbial cultures such as the now commercial KB-1® consortium that metabolize pollutants previously thought to be recalcitrant.  This discovery led to the founding of SiREM Laboratories in Guelph in 2002.  Professor Edwards and her team were awarded the 2009 NSERC Synergy Award for their highly successful partnership with Geosyntec Consultants and SiREM deploying the KB-1® microbial consortium at industrial sites contaminated with chlorinated solvents around the world.  Dr. Edwards is also the founding director of BioZone, a Centre for Applied Bioscience and Bioengineering Research at the University of Toronto and a Tier 1 Canada Research Chair in Anaerobic Biotechnology.  In 2016, she was awarded the Canada Council of the Arts Killam Prize in recognition of her outstanding career achievements and was appointed an Officer in the Order of Canada (Canada's highest civilian honor) by the Canadian Governor General in 2020.