Researchers Use Yeast to Homebrew Morphine
Researchers have successfully tweaked yeast to make it produce morphine.
John Dueber of UC Berkeley and Vincent Martin of Concordia University successfully engineered yeast to make it replicate early steps in the morphine production cycle. The yeast produced reticuline, a compound found in poppy from tyrosine, a sugar derivative. Until recently, replicating this step was the missing link in the pathway from sugar to morphine.
"What you really want to do from a fermentation perspective is to be able to feed the yeast glucose, which is a cheap sugar source, and have the yeast do all the chemical steps required downstream to make your target therapeutic drug. With our study, all the steps have been described, and it's now a matter of linking them together and scaling up the process. It's not a trivial challenge, but it's doable," said Dueber, the study's principal investigator.
The study's success hinged on availing a naturally available enzyme in beets, and using it to produce dopamine from tyrosine, which in turn can be fermented into reticuline, an alkaloid.
"Getting to reticuline is critical because from there, the molecular steps that produce codeine and morphine from reticuline have already been described in yeast. Also, reticuline is a molecular hub in the BIA pathway. From there, we can explore many different paths to other potential drugs, not just opiates," said Martin, a professor of microbial genomics and engineering.
Researchers acknowledged their study could pave the way for homebrewed drugs like heroin, which currently can only be made after poppy harvest. Regulators have commented that such bioengineering techniques should be restricted to reaping their intended benefits, aided by regulation. However, researchers have pointed out that the method to make the yeast strain can be used by just about anybody.
