The morphine of the future? (Photo: jm3/Flickr)

Last fall, two scientists reached out to tech policy expert Kenneth Oye and his colleagues for some advice. The scientists had elucidated nearly every step to a pathway that would end in the use of genetically engineered yeast to convert sugar to morphine, and they wanted guidance from Oye on how it should be regulated. A yeast-based morphine production method was imminent, the scientists reasoned, and it would lead to less expensive, less addictive, and more effective painkillers. But the scientists—John Dueber and Vincent Martin—and now Oye, worried that the method would also be a boon to the illicit opiate market, making it easier for amateurs to produce their own "home-brewed" morphine.

There are several, intermediate steps in the conversion of sugar to morphine, and by inserting various genes from poppy, beetroot, and even soil bacteria, research groups have engineered multiple strains of yeast that are capable of carrying out distinct intermediate steps. But as it stands now, no single yeast strain can perform all of these steps. Now that the work has been published in a series of papers (the most recent of which came out this week in Nature Chemical Biology), a single strain capable of carrying out the entire pathway seems all but inevitable.

“In principle,” Oye and his colleagues write in a Comment for Nature, “anyone with access to the yeast strain and basic skills in fermentation would be able to grow morphine producing yeast using a home-brew kit for beer-making.” To prevent such a scenario, Oye and his colleagues outlined four areas of yeast-based morphine production that are prime for regulation:

1. CREATE YEAST STRAINS THAT AMATEURS CAN’T USE

Yeast is easy to grow, conceal, and distribute, which makes yeast-based morphine production appealing to illicit opiate producers. But, according to the authors, yeast strains could be engineered to make the microorganisms harder to work with. Oye and his colleagues suggest that scientists design yeast strains with specific nutrient dependencies and other characteristics to ensure the strains can’t survive outside lab settings.

Another alternative: yeast strains that exclusively produce opiates without street value. An example here is thebaine, a toxic compound that can be converted to other opiates, but has no recreational or therapeutic value on its own. (Some poppy-producing countries already grow thebaine-rich varieties to discourage illegal activities.)

2. KEEP THE MATERIALS OUT OF THEIR HANDS

According to Tania Bubela, a professor at the University of Alberta’s School of Public Health and a co-author on the Nature Comment published today, there are two obstacles that make creating yeast-produced morphine very difficult: access to yeast, and, more importantly, access to the DNA sequences that need to be inserted into their genomes to give the strains the capability of converting glucose to morphine. The authors recommend warning commercial firms that synthesize the DNA to flag orders of sequences involved in this pathway for further screening. Currently, both the International Association of Synthetic Biology and the International Gene Synthesis Consortium screen requests for genetic sequences that involve dangerous pathogens, and they could easily do the same for sequences required to make opiate-producing yeast strains.

3. AMP UP SECURITY WHERE OPIATE PRODUCING YEAST STRAINS ARE BEING RESEARCHED OR WORKED ON

Securing strains with physical protections such as locks, alarms, and surveillance systems is a no-brainer, as is implementing extra security screening for laboratory personnel. Right now, so few labs work with the opiate producing strains that this has been an easy factor to regulate thus far, according to Bubela. “As the number of labs expands, then you may start to run into issues of potential for leakage [of the engineered strain] into the outside world,” she says.

4. UPDATE THE LAW

The authors suggest that the Controlled Substances Act in the United States and its equivalents abroad should be extended such that the distribution of opiate-producing yeast, like the distribution of opiates, is illegal.