We as a species would be miserable without yeast. Baker’s yeast has provided us with yeast bread for thousands of years. And I don’t even want to begin to imagine a world without beer and wine, which rely on yeast to turn sugar into alcohol.
Now researchers have turned to yeast to do the impossible: produce the cannabis compounds CBD and THC. By combining brewer’s yeast with genes from the cannabis plant, they have turned these amazing microbes into cannabinoid companies. It is a clever idea in a big move to isolate in a way and recreate many marijuana compounds, to better understand the true power of the plant.
The process goes like this. Two different yeasts produce either THC or CBD, depending on which type of enzyme they produce. Importantly, both carry the cannabis genes that produce CBGA. “CBGA is this central cannabinoid that is the mother of all other cannabinoids,” says UC Berkeley chemical engineer Jay Keasling, author of the new paper in Creation process description.
To make THC, that yeast produces CBGA, which is then converted to THCA thanks to a specific yeast enzyme. For CBD yeast, its own specific enzyme converts the mother cannabinoid CBGA into CBDA. (Alphabet soup, I know, but stay with me.) Now you have THCA and CBDA, which turn into THC and CBD with the application of heat.
The end result is no different from what happens with the cannabis plant itself. If you eat raw cannabis, it’s unlikely you’ll get high, because it’s mostly THCA. It is after you apply heat that THCA turns into THC. (Although small amounts of THCA convert to THC over time as the cannabis flower recovers.) Foods work because manufacturers first convert THCA to THC with a process called decarboxylation.
The reason why researchers and cannabis companies are interested in alternative ways of producing cannabinoids is that working with the original plant is messy and complicated. First, growing the thing takes a lot of time, water, and energy (if you’re growing it indoors). Extracting certain cannabinoids from the flower is also problematic. If you are after only CBD, for example, there is a chance that your extract may be contaminated with THC. This is a major concern if you want to isolate CBD for medicinal use—it has been shown, for example, to be edible. remarkably effective in treating epilepsy.
Having a vat of yeast extracting pure, non-psychoactive CBD promises to make production much easier. “Being able to produce that in a way that’s not contaminated with THC is pretty valuable,” Keasling said. Especially since the FDA might want to have a word with you if you accidentally dose patients with a psychoactive substance.
Cannabinoid-producing yeast can also make it easier to study cannabis in the first place. We are talking about a wild complex plant here, with more than 100 different cannabinoids known so far. Some of these compounds are more abundant than others — today’s cannabis strains come with THC, because growers have grown the strains to be more drinkable over the years. But cannabinoids like tetrahydrocannabivarin, or THCV, appear in very small amounts. “Now we’re going to have a hand in being able to produce these things in a clean way, and in a simple way, that maybe we can start to test what their functions are,” Keasling said.
Synthetic yeast has been used to combat malnutrition in other ways before. In the 1960s, researchers discovered that taxes from the bark of the Pacific yew tree can fight cancer. All is well and good, except for the Pacific yew, which conservationists fear will be destroyed at the hands of the overzealous medical establishment. But just like with cannabinoid-producing yeast, researchers engineered microbes to help make the drug deforestation-free.
For cannabinoids, the key advantage is size. The idea is that you can extract a large amount of CBD in more easily than by growing fumigation after fumigation of cannabis plants. (This is not to say that some people will not still appreciate their cannabis grow up the old way.) But to make it as effective as possible, you will need to work with higher concentrations of cannabinoids. That is, you will want to increase your yeast to produce a whole lot of product.
“Can you really concentrate it, or does it become toxic to the organisms used to form it, and therefore limited?” Ask Jeff Raber, CEO of Werc Store, a lab that isolates the components of marijuana.
Despite the manufacturing hurdles, the beauty of this type of bioengineering is that it gives researchers a powerful platform to dig into not just what each cannabinoid might be useful for — whether treating anxiety or inflammation or epilepsy — but how many cannabinoids in the plant can do. going with one another. This is known as entourage effectCBD, for example, appears to reduce the psychoactive effects of THC.
By selecting these cannabinoids in the lab, it will be easier for researchers to play with them in isolation and with each other, without having to go through the hundreds of other compounds that you will find in a flower. “Ultimately, a molecule is a molecule,” says Raber. Indeed, the cannabinoids produced from yeast are the same cannabinoids produced by plants. “It offers flexibility in formulation, it offers a wider range of benefits, and it can be broken down at a faster rate than seeds. Regulators can be much more flexible about these types of methods than those that are fields and fields and fields of plant material. “
And this does not stop at cannabinoids. What Raber and other researchers are pursuing is essentially a reconstruction of the chemical profile of cannabis. Terpenes, for example, are what give the weed its characteristic smell, however you will find these across the plant kingdom: Limonene is not abundant in cannabis, but is an abundant product of the citrus industry. The idea is that instead of going through the trouble of extracting small amounts of limonene from the cannabis plant, you can get it from lemons instead.
The ultimate goal is to be able to tailor cannabis products, such as tinctures, to customer preferences. This will allow for a personalized ratio of CBD to THC, and finally cannabinoids and other terpenes, which themselves can play a role in the entourage effect. The terpene linalool, for example, may have anti-anxiety effects.
In the near future, let’s celebrate yeast, that wonderful microbe and creator of everything good: bread, booze, and bioengineered cannabinoids.
This first story appears on wired.com.