Investigators are modifying microbe to create cannabinoids such as THC and CBD
For thousands of years human beings have used yeast to brew alcoholic drinks. But now, the scientists have engineered the same yeast to produce cannabinoids.
The discovery was published last February 27th in Nature magazine. It is about how the sugar in brewer’s yeast (Saccharomyces cerevisiae), named galactose, turns into tetrahydrocannabinol (THC), the psychoactive cannabinoid in Cannabis sativa. Altering the yeast, scientists are obtaining THC and CBD too.
Researchers expect that this fermentation process will able to produce THC, CBD and other cannabinoids found in cannabis more cheaply and efficiently than in regular marijuana plant-based cultivation. But, can this be possible? When something works perfectly well, why change it?
Investigation made before, described the construction of some parts of the cannabinoid production line in yeast, but not the whole process. However, the last research has put it all together and demonstrated that it works inside one cell. The study is being held by Hyasynth Bio in Montreal, Canada, which is a company that works to obtain cannabinoids in engineered yeast, bacteria and algae.
So far, researchers have obtained anti-malaria drugs and opiates, for commercial purposes, in the laboratory. In these cases they used yeast-grown methods too. However, the technology needed for making cannabinoids is not ready for the market. According to David Kideckel, a cannabis analyst with AltaCorp Capital in Toronto, Canada, it will take about 24 months before synthetic cannabinoids are cheap enough to be sold to either pharmaceutical companies or the general public.
In order to produce their factory in yeast, synthetic biologist Jay Keasling at the University of California, Berkeley, and other researchers experienced some genes found in S. cerevisiae, and introduced some others from five types of bacteria and from the cannnabis plant. The team needed to make 16 genetic modifications to turn galactose into inactive forms of THC or CBD. But when these cannabinoids are heated they switch in their active form. It happen the same with cannabis plants. Only when the herb is heated, the THC and CBD become active. The researchers managed to produce about 8 milligrams per liter of THC and lower levels of CBD.
However, this amount of production is far away from being competitive. It needs to be increased by at least 100 times to become cheaper than cannabis plant-extracted cannabinoids, according to Jason Poulos, chief executive of Librede, a company in Carlsbad, California, which owns the first patent on the process for producing cannabinoids from sugars in yeast.
Jay Keasling and his team have managed to engineer their yeast to transform several fatty acids into cannabinoids that don’t happen in nature. It’s possible to detect these compounds for medical properties. These new created cannabinoids could help to create interest among the different drug companies among which, a few have studied cannabis-related medicines.
However, many other researchers think this study makes no sense because yeast will never be the best way to get cannabinoids. Toronto-based Trait Biosciences, for instance, is genetically engineering cannabis to produce water-soluble cannabinoids for the beverage industry. They are even trying to modify the cannabis plants to be able to obtain cannabinoids from every single tissue of the plant and not only from the resin glands. Trait’s chief strategic officer Ronan Levy thinks that whatever you can do in yeast, you can do in the cannabis plant itself and obtain a much larger production and purity.
