Scientists: We made marijuana from yeast

Scientists have created yeast that generates the main psychoactive compound in marijuana, tetrahydrocannabinol (THC), according to a report published in the New York Times.

“This is something that could literally change the lives of millions of people,” said Kevin Chen, the chief executive of Hyasynth Bio, in the Times. Genetically modified yeast could make THC in a more efficient way than the traditional chemical synthesis of brand-name pills such as Marinol and Cesamet, according to the report.

Marijuana is finding increasing medical uses, yet there is limited evidence of how it is, or isn’t, effective against various medical conditions, according to an earlier report in the Times. Modified yeast may provide insight into what exactly takes place in marijuana’s unique chemical structure and how it could be better applied medically.

“At one level, you can say that nothing limits you but your imagination,” said Dr. Pamela Silver, a professor of systems biology at Harvard Medical School, in the recent Times report. But, she added, “This is actually really hard.”

Right now, the new biotechnology is weak compared to the greatest source of THC: the cannabis plant itself. With modern growing techniques, marijuana has become an incredibly efficient producer of THC, which sometimes constitutes as much as 30 percent of a plant’s dry weight, according to the Times.

“Right now, we have a plant that is essentially the Ferrari of the plant world when it comes to producing the chemical of interest,”Dr. Jonathan Page, an adjunct professor at the University of British Columbia, was quoted as saying in the report. “Cannabis is hard to beat.”

The Times reported that one idea is not open for research: designing yeast to help brew THC-infused beer.

“People keep asking about it,” Mr. Chen said. “But there’s bigger potential there than just making a beer.”