(ORDO NEWS) — A “switch” has been successfully inserted into a specially crafted microbe that causes genetically engineered organisms to self-destruct.
This type of mechanism is considered critical in the current development of genetically engineered organisms for medical applications, as well as the last resort mechanism for Dr. Frankenstein’s monster.
Genetically engineered microbes are on the way. Some of these organisms are being developed to treat medical diseases, others to eat toxic waste. However, such organisms typically have a limited lifespan before they can cause problems for the patient (or environment) being treated.
To combat these fears, researchers have developed various mechanisms to stop the engineered organism once it has exhausted its usefulness. Unfortunately, many of these “switches” do not work in time, or microorganisms programmed for the “switch” develop too quickly and find a way to bypass it.
Now, researchers at Washington University in St. Louis have developed a four-level “switch” that they say is practically safe.
Associate Professor of the Department of Energy, Ecology and Chemical Engineering Tae Seok Moon has already developed switches for genetically engineered probiotic organisms, including a switch that activates when a certain temperature is reached. However, according to a press release, Moon says that “in previous work, the baseline activation level was either too high or too low,” causing the organisms to self-destruct too soon or too late.
Premature self-destruction can cause the microbe to fail to complete its task, such as eating toxic waste or delivering a targeted cancer drug. Late self-destruction can cause the organisms to leave their intended target and pollute the environment, or even give the organism enough time to “evolve” past the switch, rendering it ineffective.
“Bacteria will mutate,” Moon says of this major hurdle. This restriction, he says, could negatively impact the genetically engineered microbe he wants to create to feed on plastic.
“We don’t know how many days we need to keep these microbes stable until they finish cleaning up our environment,” Moon said. “It could be a few days or a few weeks because we have so much waste.”
Moon’s latest solution, published in the journal Nature Communications, is a genetically engineered microbe that contains four different switches. In experiments, this four-pronged approach worked.
“During experiments, out of a billion microbes, only one or none can survive,” the press release explains. In addition, the switches were tested daily and remained fully active for 28 days.
It’s the best “switch” ever designed, Moon said.Moon says he would like to develop individual switches for microbes to be used in the soil, “perhaps to kill pathogens that are deadly to crops,” or perhaps develop self-destructive gut microbes to treat disease.
Whatever the future application, Moon says his new “switch” is exceptionally effective, greatly reducing some of the major concerns associated with the use of genetically engineered microbes. This is important to the development of the field, he says, as such modified organisms are ideally suited to perform a wide range of useful tasks, provided they are properly programmed.
“Bacteria may seem dumb,” Moon says, “but they can be very smart if we train them well.”
The study does not directly address the idea of implanting a switch in the DNA of a more complex organism, such as a reanimated woolly mammoth.
However, the release notes that “these experiments were also carried out on mice.” So, if scientists ever create an organism that becomes a threat, whether it’s a plastic-eating microbe or a giant demon mouse running rampant, it’s good to know that researchers will have a way to shut down those damn critters.
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