Scientists claim breakthrough in taming genetically modified E.coli bacteria

by jeeg 22. January 2015 20:32

 

Scientists have come up with a way to make genetically modified bacteria incapable of running wild in the natural world, according to two reports published Wednesday in the journal Nature. The secret is to make these microbes dependent on artificial food — synthetic amino acids that don’t occur in nature. In the wild, they’d starve and die.

The scientists believe this is a critical step in making synthetic organisms more attractive to industry and far less likely to pose even a hypothetical ecological threat.

This work has been done only on bacteria, specifically E.coli, and is a long way from being applied in plants and animals. But the technique is “a compelling solution to biological containment,” said George Church, who co-wrote one of the two papers and is a professor of genetics at Harvard Medical School.

The other paper comes from a team led by Farren Isaacs, a Yale professor who used to work with Church’s lab at Harvard. They have formed a private company, EnEvolv, to market their laboratory innovations. Church said this new technique will be attractive to companies that use modified bacteria to make chemicals, or in biohazard remediation, such as cleaning up toxic waste sites.

The modified bacteria are designed to be resistant to viruses, making them more robust. That modification could give the bacteria a competitive advantage in the wild if not constrained by the dependence on the artificial amino acids.

“On the tactical side, this is the first time that anybody had gotten an organism that can be very robust but nonetheless not escape from the laboratory,” Church said in an interview.

Genetic ma­nipu­la­tion of organisms, including splicing of genes from one species to another, has been a source of innovation and controversy since the 1970s. Genetically modified organisms (GMOs) routinely are used to create insulin and to produce biofuels. Corporate agriculture is heavily dependent on GM crops such as corn and soybeans. In academic laboratories, scientists are creating what essentially are new species — and even new kingdoms of life.

The debate over GMOs is entangled in ideological issues that include objections to corporate agriculture, in which a large company has ownership of a modified species and typically plants crops in vast monocultures. There are recurring questions about who, exactly, is benefiting from these new technologies.

But Steve Benner, who works on synthetic life at the University of Florida, considers GMOs inherently unfit to compete against natural organisms. Life has evolved to fill every environmental niche. Organisms are optimized for their environment: If they could prosper better via mutation, they would have done so.

“It is like climbing a fitness landscape; natural Darwinism has gotten to the local top of Mount Hood. Any step away goes downhill, in fitness,” Benner wrote in an e-mail.

Church said in an e-mail that he agrees with Benner that current GMOs won’t survive long in the wild.

“But multi-virus-resistant [GMOs] are very likely to be an exception (and an industrially attractive one at that),” Church said. “We wanted to get the safety part in place before we take the next step in making full resistance to all viruses.”

Isaacs said this is an important development at the beginning of what he calls “the biotech century.” Isaacs listed several fundamental challenges facing society: the search for renewable sources of energy, the need to feed a hungry planet and the quest for new drugs to combat disease.

“I think a lot of the solutions are going to be rooted in technology. It’s important that, as [genetically modified] organisms start to be reprogrammed to address those challenges, that at early states we engineer important safety measures,” Isaacs said.

Biocontainment is only one element of the debate over the use of GMOs, said David Guston, a professor of politics and global studies and the co-director of the Consortium for Science, Policy and Outcomes at Arizona State University.

“A whole lot of work has to be done for it to be a game changer, and even if that work is successful, it’s still a framework that many people could object to,” Guston said. “It’s a technical fix for only one portion of people’s potential ecological objections, or social or ethical objections.”

Joel Achenbach , Washington Post

 

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