Crude petroleum releases a strong odor distinctive of the toxins that make up the fossil fuel. Sprinkle mushroom spores over the crude and let it sit for two weeks in an incubator, and surprise, the petroleum and its smell will disappear.
“The mushrooms consumed the petroleum,” said Mohamed Hijri, a professor of biological sciences and researcher at the University of Montreal’s Institut de recherche en biologie végétale (IRBV).
Hijri co-directs a project promoting nature as the number one ally in the fight against contamination. Fellow co-director is with B. Franz Lang, who holds the Canada Research Chair on Comparative and Evolutionary Genomics and is a professor at the university’s Department of Biochemistry. By using bacteria to stimulate the exceptional growth capacity of certain plants and microscopic mushrooms, Hijri and Lang said created in situ decontamination units able to successfully attack the most contaminated sites on the planet.
The recipe is simple. In the spring, they plant willow cuttings at 25-centimeter intervals so the roots dive into the ground and soak up the degrading contaminants in the timber along with the bacteria. At the end of the season, they burn the stems and leaves and end up with a handful of ashes imprisoning all of the heavy metals that accumulated in the plant cells. Highly contaminated soil will clean up after a few cycles.
“In addition, it’s beautiful,” said Hijri pointing to a picture of dense vegetation covering the ground of an old refinery after just three weeks.
Thanks to the collaboration of an oil company from the Montreal area, the researchers had access to an area where practically nothing can grow and where no one ventures without protective gear. This is where Hijri collected microorganisms specialized in the ingestion of fossil fuels.
“If we leave nature to itself, even the most contaminated sites will find some sort of balance thanks to the colonization by bacteria and mushrooms. But by isolating the most efficient species in this biological battle, we can gain a lot of time.”
This is the visible part of the project, which could lead to a breakthrough in soil decontamination. The project is called Improving Bioremediation of Polluted Soils Through Environmental Genomics and it requires time-consuming sampling and fieldwork as well as DNA sequencing of the species in question. The project involves 16 researchers from the University of Montreal and McGill University, many affiliated with the IRBV. The team also includes four researchers, lawyers and political scientists, specializing in the ethical, environmental, economic, legal and social aspects of genomics.
The principle comes from a well-known process in the sector called phytoremediation that consists in using plant matter for decontamination.
“However, in contaminated soils, it isn’t the plant doing most of the work,” Lang said. “It’s the microorganisms i.e. the mushrooms and bacteria accompanying the root. There are thousands of species of microorganisms and our job is to find the best plant-mushroom-bacteria combinations.”
Botanist Michel Labrecque is overseeing the plant portion of the project. The willow seems to be one of the leading species at this point given its rapid growth and premature foliation. In addition, its stem grows even stronger once they cut it. Therefore, there is no need to plant new trees every year. However, they still need to determine the best willow species.
By investing C$7.6 million over three years, Genome Canada, Genome Quebec and other partners are expecting concrete results in the soil decontamination market, estimated at C$30 billion in Canada alone.
“The fact that the project ranked second amongst the best projects in the country took us by surprise,” said Lang.