GMOs on a leash: scientists engineer bacteria that can’t survive in the wild uncontrolled
Two teams of researchers from the US recoded the genome of the E. coli bacteria such that it dies when it runs out of synthetic chemical, unavailable in nature. This way, it's impossible for the bacteria to spread into the wild uncontrolled. Effectively, this self-destruct measure puts GMOs on a tight leash!
Though GMOs are generally believed to be safe, they’re still shrouded in controversy. Partly because the general public is misinformed on what GMOs are (they’ve been around for thousands of years, we’re only tweaking them much better now in the lab – see artificial selection), but also because there are some genuine and reasonable ethical issues surrounding them. A stronger, pest-resistant GMO crop can spread and put wild strains “out of business”. Controlling them can be a very challenging issue, since life is very good at overcoming obstacles. After all, replication and survival are the most fundamental guides hard-coded in the DNA. But two teams of researchers from the US may have found an elegant solution. Each team independently recoded the genome of the E. coli bacteria such that it dies when it runs out of synthetic chemical, unavailable in nature. This way, it’s impossible for the bacteria to spread into the wild uncontrolled. Effectively, this self-destruct measure puts GMOs on a tight leash!
Genetically engineered micro-organisms are used in Europe, the US and China to produce drugs or fuels under contained industrial conditions. As for plants, much research has focused on making enhanced crops that are more resistant to pests, have greater nutrient content or contain a new nutrient altogether such as the case of Golden Rice, which was engineered to yield Vitamin A.
Genetically modified micro-organisms are the most worrisome since they might outcompete native strains, with unintended ripple effects on the environment. For instance, engineered bacteria have been tested with very good results for cleaning oil spills, but while they might prove useful in averting an instance of an ecological disaster, they might trigger another one.
“I view us right now at the beginning of the biotech century, where I think a lot of solutions to defining global challenges . . . are in large part going to result from advances in biotechnology,” said Farren Isaacs, assistant professor of molecular, cellular, and developmental biology at Yale, who led one of the studies. “In many ways, what we are doing is trying to be a step ahead of any challenges we might face.”
The Harvard and Yale scientists grew about one trillion bacteria and found that not one could survive without the essential synthetic amino acid.
“We’re changing the whole genome,” Church said. “So all genes, including the ones involved in producing whatever chemical you’re interested in, all those genes get changed. None of these can go in or out functionally.”
The US researchers describe their research, published in Nature journal (1 and 2), as a “milestone” in synthetic biology.
“This work provides a foundation for safer GMOs that are isolated from natural ecosystems by a reliance on synthetic metabolites,” Church says.
Yet, not everybody is convinced by the two studies.
“The problem is that we cannot quickly determine if every single GMO that is produced is absolutely safe or absolutely unsafe to people and the environment. The last thing we want to have happen is to figure out that something is dangerous through accidental release, after it is too late,” said Karmella Haynes, an assistant professor in the School of Biological and Health Systems Engineering at Arizona State University. “I feel that this research represents a step-change towards building reliable control switches for GMOs.”
Jaydee Hanson, policy director of the International Center for Technology Assessment, said that the research was limited because these first tests were done in traditional laboratory environments.
“The basic idea in them is that can we engineer something so that if it gets out into the environment, or in the case of probiotics — when it’s in your body — so it doesn’t morph into something else,” Hanson said.
“I hope their next step would be to run the experiment longer, and to make sure that you’re not having any problems after multiple generations.”