Enzymes’ Journey to remediate Conventional and Unconventional Oils


Canada is the world’s fourth-largest producer of petroleum in 2020 and the largest supplier of crude oil imports to the United States using transmission pipelines and train rails. Mainly, crude oils are classified into conventional and unconventional oil that can be categorized into the following groups: heavy oil, extra-heavy oil, oil sand (bitumen), and oil shale (Kerogen). The behaviour of conventional and unconventional oil in terms of ecotoxicity and biodegradation might be different in aquatic and terrestrial environments. A multiplication of factors including aging and densification of pipeline networks and increased rail transport is not always adequate cars have increased the risk levels of high-impact oil spills and catastrophic emergencies have occurred. When petroleum hydrocarbons are released into the environment, they can lead to serious human and ecosystem hazards necessitating urgent clean-ups. Following the rapid response to oil spills to protect people, property, and the environment, a series of physicochemical techniques, such as chemical oxidation, extraction, washing, and microbial biosorption has been developed for soil and water remediation. Bioremediation is a green technology that uses microorganisms or microbial enzymes to degrade and detoxify environmental contaminants. However, the limitations and challenges for petroleum hydrocarbon bioremediation in contaminated sites remain at large. Further research and advances are required to determine which method is more effective for the biodegradation of petroleum contaminants. Recently, biosurfactant and degradative enzymes mediated oil degradation have attracted significant attention in recent years from researchers, to overcome issues regarding the limited bioavailability of soil-bound hydrocarbons and slow rate of bioremediation for recalcitrant fractions in the environment.

Depending on the type of contaminant, type of the spill (land-based or oil spill in aquatic environments), and environmental conditions, different types of enzymatic treatment methods for bioremediation of petroleum hydrocarbon polluted ecosystem can be applied In our previous study, crude enzyme and biosurfactant cocktail from Alcanivorax borkumensis were applied for diesel decontamination. This cocktail exhibited the highest ability and degraded up to 80 % of the targeted contaminant. To decrease the industrial scale operating and enzyme production cost, data of different batches carried out in smaller computer-controlled bioreactors, as well as soil column tests can provide the maximum information on potential limitations at reasonable costs and time.

Most recently, we formulated a cold-active enzyme cocktail from isolated bacteria for bioremediation of the xylene-contaminated sites in cold regions. These contaminated sites have received significant attention because of their susceptible natural environment to human impacts. Cold-adapted enzymes can degrade xylene-contaminated soil (initial concentration of 13,000 mg/kg) at low temperature (<10°C) which can be considered an effective enzymatic treatment agent.

As for the unconventional oil spills, the plume of this oil will sink, and when it interacts with the water table, less concentrated plumes move into the water table. Exploiting bio-carriers, nutrients, and degrading microbes and mixing them with formulated slow-release particles are biotechnological approaches applied to limit the oil-impacted seafloor area. However, the development of innovative devices and/or processes for the recuperation of oil and attenuation measures are necessary to gather submerge degraders and submerge oils in a common location. Portable oil spill cleaning devices equipped with enzyme-immobilized compartments can be applied to adsorb contaminants and remediate contaminated water, and the same has been explored in our group.

The Presenters:

Satinder Kaur Brar, Ph.D.

Professor, Department of Civil Engineering, York University.

Prof. Satinder Kaur Brar is the James and Joanne Love Chair in Environmental Engineering at York University. Her research is on the intersecting areas of environmental engineering and its impact on the overall well-being of the global community. She primarily works in the two converging fields of value-addition of wastes and removal of emerging contaminants. Many national and international awards and honors have been bestowed on her that prove her research mettle. Notable ones being, in 2021, Best paper award, and in 2019, Eddy Principles/Processes Wastewater Medal winner, honored by the Water Environment Federation; in 2017, her research on “Novel and Advanced Hybrid Oxidation and Enzymatic Technologies for Emerging Trace Environmental Contaminants” were awarded the Grand Prize in University Research for Excellence in Environmental Engineering and Science by the American Academy of Environmental Engineers and Scientists (AAEES). She was recently inducted into the European Academy of Sciences in 2021 and as well is a member of the College of New Scholars, Scientist and Artists of the Royal Society of Canada, since 2014. She leads the Bioprocessing and NanoEnzyme Formulation Facility (BANEFF) at York University and this unit has successfully led to the training of 72 HQP (including 45 undergraduates and summer interns). Currently, she is supervising 4 PDFs, 2 research associates, one research assistant, 11 Ph.D.s and 2 M.Scs. She has published more than 400 articles, edited 12 books and at least 55 invited talks to her credit.

Phil Dennis, M.A.Sc.

Principal Scientist, SiREM

Phil is a Principal Molecular Biologist with more than 20 years of experience focused environmental microbiology, molecular genetic testing, enhanced bioremediation and technology commercialization. He currently directs the molecular testing services, next generation sequencing and is the innovation lead for SiREM’s research and development program. He has also played a leading role in developing relationships with many universities and serves on the Board for University of Waterloo Center for Microbial Research.