Volume 94 Issue 40 | p. 8 | News of The Week
Issue Date: October 10, 2016

Microbial enzyme could help clean up explosives

New way to detect and destroy the increasingly popular munition 2,4-dinitroanisole
Department: Science & Technology
News Channels: Biological SCENE, Environmental SCENE
Keywords: pollution, explosives, DNAN, 2,4-dinitroanisole, bioremediation

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 coworkers 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 (Environ. Sci. Technol. 2016, DOI: 10.1021/acs.est.6b03044).

The enzyme converts DNAN into 2,4-dinitrophenol, whose yellow color indicates DNAN’s presence. The researchers first immobilized 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.

“Defense 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
ISSN 0009-2347
Copyright © American Chemical Society
Comments
Tariq Bhatti (Mon Oct 10 15:54:49 EDT 2016)
This is an interesting method to detect nitroanisoles but its application in environmental remediation should give pause. The product from the enzymatic hydrolysis, 2,4-dinitrophenol is a metabolic poison with both acute and chronic toxicity. What is the environmental fate of nitrophenols in soil and groundwater?

Ryan Cross (Fri Oct 14 13:33:25 EDT 2016)
In the study, Jim Spain notes that conversion of DNAN to 2,4-DNP alone is not detoxification. He also informed me that "DNP is pretty biodegradable, and the original organism has all the enzymes for mineralizing DNP."
Robert Buntrock (Fri Oct 14 10:06:13 EDT 2016)
Curiously, 2,4-dintiroanisole is not in The Merck Index (15th ed.). The Wikipedia reference indicates that 2,4-DNA is described as pale yellow needles so the appearance of a yellow color when dinitrophenol is formed is not very definitive.

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