Marijuana compounds brewed using yeast by Canadian biotech firms

Canadian biotechnology companies are developing new medical marijuana products that don't come from marijuana plants. Instead, they're brewed, like beer, using yeast. And they could lead to new medical treatments for a wider range of conditions.

Yeast fermentation technique allows researchers to isolate cannabinoids for treatment of different diseases

Kevin Chen's company, Hyasynth, has successfully produced the cannabinoids CBG and CBGV from genetically engineered yeast, and he says this could be a precursor to other major and minor cannabinoids. (Emily Chung/CBC)

New medical marijuana products produced by yeast could soon be on the market, the co-founder of a biotech company says. That could potentially lead to a wider range of cannabinoid-based drugs that proponents say could be more effective for treating certain medical conditions than medical marijuana itself.

Cannabinoids are chemical compounds found in marijuana. Kevin Chen's Montreal-based company,  Hyasynth, has successfully made the  cannabinoid  cannabigerol (CBG) from genetically engineered yeast, and he says this could be a precursor to other major and minor  cannabinoids.

The appropriate use of medical marijuana has been a controversial topic, with many arguing that further research is needed to evaluate its efficacy as a treatment for a variety of ailments. 

In Canada, where the Liberal government has said it will legalize marijuana, medical marijuana is already used to treat a variety of conditions and symptoms, including lack of appetite in people with HIV/AIDS and nausea in those undergoing cancer treatment.

The most well-known cannabinoid is tetrahydrolcannabinol, or THC, which is approved by the U.S. Food and Drug Administration to treat nausea and improve appetite. It's found in large amounts in marijuana plants, which is the reason why medical marijuana is often prescribed to treat nausea and increase appetite.

But other cannabinoids, like cannabidiol (CBD) and cannabigerol (CBG) may have the potential to be potent treatments for other conditions as well. CBG also has its own medical properties. But it can also be easily chemically converted into other cannabinoids, including THC.

Marijuana produces lots of THC and CBD, but isn't a very good source of some of the minor cannabinoids. (CBC)

Hyasynth's researchers aren't the only ones working to brew cannabinoids using yeast. In a paper published in Biotechnology Letters in December, German biochemists announced they had genetically engineered yeast to produce THC.

And another Canadian firm, Anandia Labs, is well on its way toward brewing its own yeast-produced cannabinoids.

Chen says genes from marijuana are inserted into the yeast genome, where they produce the enzymes that create the cannabinoid. Before insertion, the yeast's metabolic systems are engineered "to get it to produce your molecules instead of its own molecules."

Yeast-produced cannabinoids could yield some impressive advantages in the pharmacological world.

Perhaps most exciting is the ability to isolate different compounds for study and treatment of particular diseases. Cannabinoids found in very small concentrations in marijuana plants could also be produced in more potent dosages.

"Marijuana produces lots and lots of THC, and lots and lots of another compound called CBD, but it also isn't a very good source of some of the minor cannabinoids," says Jonathan Page, CEO of Anandia Labs and a University of British Columbia botany professor.

Cost efficiencies?

Chen says growing cannabinoids using yeast is more efficient than artificial chemical synthesis. (Artificially produced THC pills are already on the market).

These yeast cultures were created by Hyasynth. The colour difference is from different kinds of ingredients in the media. (Courtesy Kevin Chen)

"Natural molecule production is done pretty well by nature, and so we're working with that as a basis as opposed to just trying to produce things straight from petroleum starting materials or something like that."

It's been suggested that producing cannabinoids through yeast could have a lower production cost than other methods, but Page says that's still up for debate.

"We don't have enough real data to support the fact that fermentation would be cheaper than chemical synthesis or plant production, so I can't really say that's going to be a clear advantage."

Chen says cannabinoid-producing yeast yields more consistent results than marijuana plants, even specialized strains. Factors like when a plant is harvested and how much light and water it gets can affect its drug profile.

"Maybe you're growing the same strain twice on two different occasions and maybe there's a slight difference in the temperature and that results in a big difference in the end product."

Still a place for plants

As beneficial as isolated cannabinoids may be, marijuana plants still have their place.

"Plants are some of the cheapest chemical production systems on the planet," says Page.

Hyasynth's cannabinoid-producing yeast is seen under a microscope. (Courtesy Kevin Chen)

With just soil, water and light, you can grow a plant that can be made of 25 per cent or more, by dry weight, of the major chemical compounds like THC and CBD, he says.

"The other advantage is that plants are very easily scalable," he says, "in the sense that if you can grow two plants, you can grow a million plants … it's just a matter of planting more. Whereas scaling up in biotech systems like yeast fermentation can be quite technically challenging."

With momentum for increased medical marijuana research building, Chen says that in the near future, "you're going to see a lot more attention being paid towards these kinds of drugs."

His company is currently looking for potential commercial partners who can help get Hyasynth's products to market. He acknowledged they would have to be tested and approved by regulators before hitting store shelves. Still, he believes all that could happen within the next year.

The federal government is currently reviewing its medical marijuana distribution regulations after a judge struck down a law mandating that cannabis be distributed only by licensed providers through the mail.