London (17.04.17) –
This may not be GM-agriculture in the sense that people usually expect but
it is certainly about agriculture and equally about a valuable use for GM-technology.
One reported result of armed conflict, especially in the Middle East, is that vast acreages of agricultural land have been sown with landmines: land recently recaptured from Isil represents “one of the toughest challenges we’ve faced in decades, and this whole region is just one huge minefield,’ said Sean Sutton, the international spokesman for the Mines Advisory Group (MAG), a British charity specialising in mine clearance (1). The Times commented that the “prize at stake is a cheap and safe way for people without expert training to clear some of the 100 million mines buried around the world, which maim or kill as many as 20,000 people a year. More than 50,000 landmines are still buried across 185 square miles of Croatia, where they have caused at least 500 deaths since the country’s war of independence two decades ago” (2).
Unless speedier methods than manually-operated electromagnetic detectors are developed, the mines might take decades to clear. That would leave countless farmers with the unenviable choice of abandoning their lands for long periods of time, with obvious and often devastating economic losses, or taking the risk of inadvertently setting off explosions with all the unfortunate consequences which then might ensue.
So a paper from an Israeli group offering another way is most welcome. Although not a totally new idea (3), the new proposal envisages scattering over the minefield bacteria genetically modified to fluoresce in the presence of explosives leaking from the mines. The actual trigger molecules are 2,4,6-trinitrotoluene (TNT) and 2,4-dinitrotoluene (DNT), a degradation product of TNT. Fluorescence is stimulated by irradiation with an appropriate laser beam shone from a drone flown over the hazardous area; a camera on the drone detects the fluorescence and reports locations back to base (4).
In a trial run, Belkin et al. “encased about 105 E. coli biosensor cells in 3-mm diameter alginate beads and spread about 8 beads per cm2 on top of the soil or sand in which anti-personnel mines has been buried. Alginate encapsulation enables diffusion of trace amounts of explosives into the sensor cells and provides a semi-liquid environment in which cells can remain viable for several hours”. The method successfully detected 13 samples buried in sand but not an explosive-free control or mines buried for only 5 days in garden soil. Whether the failure to detect the mines in soil was a consequence of the sort burial time or of some interfering aspect of the soil was not resolved.
While clearly there would be a good deal of development work before the system could be ready for use in the field, the report represents a good start for dealing with a very difficult and widespread problem.
1. Colin Freeman (25.02.17). The British charity clearing up landmines in Iraq. The Telegraph (http://www.telegraph.co.uk/news/2017/02/25/british-men-risking-lives-clear-iraqs-landmines/)
2. Oliver Moody (12.04.17). Life-saving GM bacteria sniff out landmines. The Times (https://www.thetimes.co.uk/article/life-saving-gm-bacteria-sniff-out-landmines-jrb9rtlpq)
3. Burlage, R.S., Patek, D.R. and Everman, K.R. (26.10.99). Method for detection of buried explosives using a biosensor; US patent 5972638 (http://www.google.co.uk/patents/US5972638)
4. Shimshon Belkin, Sharon Yagur-Kroll, Yossef Kabessa, Victor Korouma, Tali Septon, Yonatan Anati, Cheinat Zohar-Perez, Zahi Rabinovitz, Amos Nussinovitch and Aharon J Agranat (April 2017). Remote detection of buried landmines using a bacterial sensor. Nature Biotechnology, 35(4), 308 (https://www.nature.com/nbt/journal/v35/n4/pdf/nbt.3791.pdf)