Marijuana compounds brewed using yeast by Canadian biotech firms

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 ofcannabinoid-baseddrugs that proponents say couldbe more effective for treating certainmedical conditions than medical marijuanaitself.

• Revised medical marijuana manual lists many adverse effects

• Medical marijuana dispensing eyed by Canadian Pharmacists Association

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

The most well-knowncannabinoidis tetrahydrolcannabinol, orTHC, 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, whichis the reason why medical marijuana is often prescribed to treat nausea and increase appetite.

But othercannabinoids, likecannabidiol(CBD) andcannabigerol(CBG)may havethe potential to be potent treatments for other conditions as well.CBG also hasits own medical properties. But it can also be easily chemicallyconverted into othercannabinoids,including THC.

Hyasynth's researchers aren't the only ones working to brewcannabinoidsusing yeast. Ina paper published in Biotechnology Lettersin December, German biochemists announced they had genetically engineered yeast to produceTHC.

And another Canadian firm, Anandia Labs, is well on its way toward brewingits own yeast-producedcannabinoids.

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

Yeast-producedcannabinoidscould yield some impressive advantages in the pharmacological world.

• B.C. pot activist Dana Larsen charged with trafficking marijuana in Calgary

• Medical marijuana groups say increase in veterans' pot claims no shock

Perhaps most exciting is the ability to isolate different compounds for study and treatment of particular diseases.Cannabinoidsfound 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 minorcannabinoids," says Jonathan Page, CEO of Anandia Labs and a University of British Columbia botany professor.

Cost efficiencies?

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

"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 producingcannabinoidsthrough 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 isolatedcannabinoidsmay be, marijuana plants still have their place.

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

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 betested 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 licensedproviders through the mail.