Yeast can produce THC, CBD, novel cannabinoids

"The economics look really good," researcher Jay Keasling said. "The cost is competitive or better than that for the plant-derived cannabinoids."

By Brooks Hays

Feb. 28 (UPI) -- Scientists at the University of California, Berkeley have bioengineered yeast to produce THC and CBD, the two main ingredients in cannabis. Researchers also engineered the yeast to synthesize novel cannabinoids not found in the marijuana plant.

THC is the mind-altering ingredient in marijuana, while CBD is the non-psychoactive compound. Studies have shown both have medicinal qualities, which is why many states have legalized medical pot.


Makers of THC and CBD products currently rely on expensive extraction methods to access the cannabis compounds, but the latest breakthrough suggests a cheaper, more efficient production method.

"For the consumer, the benefits are high-quality, low-cost CBD and THC: you get exactly what you want from yeast," Jay Keasling, a professor of bioengineering at UC Berkeley, said in a news release. "It is a safer, more environmentally friendly way to produce cannabinoids."

While more and more research into the medicinal benefits of CBD and THC is being conducted, analysis of other cannabinoids, compounds found in Cannabis sativa in only tiny qualities, is difficult.

According to the new study, published this week in the journal Nature, the latest breakthrough offers "the possibility of new therapies based on novel cannabinoids: the rare ones that are nearly impossible to get from the plant, or the unnatural ones, which are impossible to get from the plant."


The chemical extraction process is responsible for a variety of environmental problems, including high levels of energy use and the production of toxic byproducts. Extracting chemicals from pot plants, of course, requires marijuana cultivation, another industry with a problematic environmental track record.

Marijuana farms are increasing in size and scope, and in California, commercial marijuana cultivation operations have been blamed for polluting local waterways with pesticides and fertilizer runoff. Marijuana crops are also water-hungry, putting added pressure on California's limited water resources.

Scientists were able to turn yeast into a cannabinoid factory by engineering it to turn sugar into other chemicals that react with added enzymes. Initial tests showed the enzyme that normally synthesizes CBGA, the mother of all cannabinoids, doesn't work in yeast.

Researchers looked in marijuana for other cannabinoid-producing enzymes and found prenyl transferase. It took to yeast immediately.

"It worked like gangbusters," Keasling said.

Next, scientists added additional enzymes to create specific pathways for the production of THC and CBD. The team of researchers also added other enzymes to produce CBDV and THCV, less well known cannabinoids that could have medicinal qualities.

Keasling and several of his colleagues founded a company that is licensing the research and working to commercialize the yeast fermentation process.


"The economics look really good," Keasling said. "The cost is competitive or better than that for the plant-derived cannabinoids. And manufacturers don't have to worry about contamination -- for example, THC in CBD -- that would make you high."

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