Gallivan admits that there are several hurdles to overcome before his reprogrammed bacteria could clear up atrazine pollution in the field. For once, the cells get stuck once they have eaten all the atrazine. This could be tackled by reengineering the switch so that bacteria stop moving once they encounter atrazine and start again once they have cleared it. The system might also have to be transplanted into hardier bacteria that are able to survive in the harsh conditions at polluted sites, and further modifications might be necessary to improve the sensitivity to atrazine.
John Simon of the international consulting firm WSP Environment & Energy says that even with increased sensitivity, “probably the greatest application for such a biological remediation approach for atrazine would be at the location where the chemical is manufactured or managed in concentrated form–because otherwise the area is so extensive that it would be difficult to do economically.”
Simon expects that any field application is a long way off due to regulatory concerns about genetically modified organisms.
Víctor de Lorenzo, of the Molecular Environmental Microbiology Laboratory in Madrid, Spain, shares this concern, but believes that using synthetic biology to equip genetically modified organisms with tightly controlled specific functions is a good way to address safety issues. “This is an incredibly exciting demonstration of how you can rewire and effectively program bacteria to make them behave in the way that you want,” he says.
Warren Dick, a professor of soil science at Ohio State University, say that the approach “is very interesting and certainly has potential for increased removal from atrazine-contaminated sites.”