Microbial enzyme could help clean up explosives

Scientists have been seeking ways to remediate soil at military testing grounds and other places that have been contaminated with explosives. Now, a research team has devised a method for detecting and destroying the explosive compound 2,4-dinitro­anisole (DNAN) that’s inspired by bacteria. Jim Spain of the University of West Florida and co-workers previously discovered an ether hydrolase enzyme in the bacterium Nocardioides sp. JS1661, which they found in wastewater from a DNAN manufacturing plant. In a new study, Spain’s group found that the hydrolase can function outside the microbe, without any added cofactors. The enzyme converts DNAN into 2,4-dinitrophenol, whose yellow colour indicates DNAN’s presence. The researchers first immobilised the enzyme in silica to demonstrate that it could be used to detect DNAN in waste streams or used in bioreactors to destroy DNAN. They also coated cellulose filter paper with the enzyme so that it could be used in the field to signal DNAN contamination. “Defence departments are interested in employing DNAN in their arsenal because it is safer to handle and is less sensitive than TNT and other traditional explosives,” says Jalal Hawari of Montreal Polytechnic who also studies microbes for cleaning up explosives. “This work came at a perfect time,” he says. Spain hopes to avoid the land and groundwater contamination that’s happened with other explosives. He says: “For the first time, we are being proactive” about finding ways to biodegrade explosives before they’re widely used.

Chemical & Engineering News, 10 October 2016 ;http://pubs.acs.org/cen/news ;