By Geoff Lee
University of Saskatchewan biologists have discovered a fungus that could turn barren tailings in the Athabasca oilsands into a lush landscape of grasses and clover.
TSTh-20-1 is the code name for a unique strain of Trichoderma harzianum fungus that researchers isolated from the roots of weeds that grew as a pioneer on coarse oilsand tailings.
Few plants grow there since the extraction process of bitumen from oilsands uses heat and chemicals that rob the coarse tailings of almost all of their nutrients.
“Coarse tailings have no plant minerals. They are essentially nutrient free,” explained biology professor Susan Kaminskyj who heads the research team.
“There is no nitrogen or phosphorus to tap in – no potassium, no organic carbon. The extraction of the hydrocarbons removes all the nutrients. It is remarkably close to 100 per cent nutrient-free.”
“The part the extraction process doesn’t get is some hydrocarbon that makes the coarse tailings sands hydrophobic, so they don’t absorb water.
“The little bit of hydrocarbon left is also toxic to plant growth.”
The TSTh20-1 first isolated by graduate student Xiaohu Bao is the only strain of Trichoderma harzianum (so far) that allows plants to grow on coarse oilsands tailings.
“This is analogous to people having invisible talents such as playing the piano,” said Kaminskyj who cannot yet fully explain how the fungi support life in low nutrient coarse tailings. Her team has several hypotheses.
“Isn’t that the $64,000 question?” she asks.
“The important thing is that if you colonize a plant seed with this fungus or a young seedling and plant it on tailings sand, it will grow watered with rain water and no added fertilizer.
“We have a cost effective, efficient way of growing grasses and other things on tailings sand to allow them to recover a soil community before we try to turn it into forest.”
The U of S research team can grow and harvest TSTh20-1 spores in the lab and use them to coat and colonize seeds of other plants before planting them.
The university is patenting the use of TSTh20-1 for enhancing plant growth on dry and low nutrient soil. Research by graduate student Tim Repas is extending this.
TSTh20-1 is able to confer its tolerance for delicate plants to grow on coarse oilsands tailings without adding fertilizer.
“What we do is take the spores from the fungus and wash them onto seeds then plant the seed,” said Kaminskyj on how to colonize grasses, grains and even vegetables.
“It can be any seed. We typically used tomatoes, not because we want to eat tomatoes that are grown on oilsands tailings, but because they grow well in a plant growth room and they need lots of water and mineral nutrients.
“We didn’t give them any fertilizer and we grew beautiful tomatoes.”
Controlled experiments with the TSTh20-1 fungus improved seed germination in oilsand tailings and gave good early seedling growth.
“So clearly, it is allowing the plant somehow, in ways we don’t entirely understand, to maximize its use of whatever is available in that sand. It does increase root growth,” said Kaminskyj.
“It increases water use efficiency for the plant. The plant makes the best possible use of all the water that comes its way. We are actively researching this. The good thing is we can use it before we understand all the details.”
Researchers at Washington State University have found other fungal strains with the potential to revitalize wetlands, hot soils and salty soils.
The U of S research began in 2005 and is funded by the Natural Sciences and Engineering Research Council of Canada. The findings will be published early in 2014.
Kaminskyj hopes to attract interest from oilsands companies to run field trials. This is a practical option to high cost engineering solutions for site remediation.
“Companies put a layer of plant material and uncontaminated soil on top about a metre thick. Then they put on ordinary grass seed and fertilizer over and over and over,” she said.
“What we would do is just add essentially our treated seeds and go away.
“So rather than millions of dollars per square kilometre, we are talking about thousands of dollars per square kilometre – small thousands.
“I am confident that if we can get someone to listen and share our data, they will say ‘perhaps we can give you a couple of hectares where you can run some field trials,’ ” said Kaminskyj.
“That’s what I’d really like – to take it out of the growth room and into real life situations to test our strains and see if they work.”
Seed companies are also interested in marketing TSTh20-1, but they too require field data to commercialize it.
“Field data has to be oilsands tailings, so it all comes back to having a partnership with an oilsands company or with a consortium of oil sands companies,” said Kaminskyj.
“Somehow though they haven’t been receptive.”
Kaminskyj is hopeful that will change given there are about 740 square kilometers of coarse oilsands tailings that need to be reclaimed to a natural stage.
According to Alberta Environment and Sustainable Resource Development, approximately 10 per cent of the active mining footprint has been or is being reclaimed by industry in the province since 1960.
It took until 2008, however for Syncrude to receive the first reclamation certification in the Canadian oilsands industry for a 104-hectare area known as Gateway Hill.
“I would like to be able to help them do more of it. There is also an equal area of fine tailings in tailing ponds,” said Kaminskyj.
Suncor is using its patented TRO technology process to convert fluid fine tailings more rapidly into a solid landscape suitable for reclamation.
“It turns out we also have fungi that grow well in oilsands process water,” added Kamiskyj
“What we are trying to do is reduce the size of the footprint. Even if all you ever grow is a meadow that has grasses and clovers and other things, we are ahead.
“They will also stabilize the soil and return organic matter to the soil.”
This article originally appeared in the January 2014 issue of Pipeline News.