Microbial degradation of explosives: biotransformation versus mineralization (original) (raw)
Abstract
The nitroaromatic explosive 2,4,6-trinitrotoluene (TNT) is a reactive molecule that biotransforms readily under both aerobic and anaerobic conditions to give aminodinitrotoluenes. The resulting amines biotransform to give several other products, including azo, azoxy, acetyl and phenolic derivatives, leaving the aromatic ring intact. Although some Meisenheimer complexes, initiated by hydride ion attack on the ring, can be formed during TNT biodegradation, little or no mineralization is encountered during bacterial treatment. Also, although the ligninolytic physiological phase and manganese peroxidase system of fungi can cause some TNT mineralization in liquid cultures, little to no mineralization is observed in soil. Therefore, despite more than two decades of intensive research to biodegrade TNT, no biomineralization-based technologies have been successful to date. The non-aromatic cyclic nitramine explosives hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX) and octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine (HMX) lack the electronic stability enjoyed by TNT or its transformed products. Predictably, a successful enzymatic change on one of the N–NO2 or C–H bonds of the cyclic nitramine would lead to a ring cleavage because the inner C–N bonds in RDX become very weak (<2 kcal/mol). Recently this hypothesis was tested and proved feasible, when RDX produced high amounts of carbon dioxide and nitrous oxide following its treatment with either municipal anaerobic sludge or the fungus Phanaerocheate chrysosporium. Research aimed at the discovery of new microorganisms and enzymes capable of mineralizing energetic chemicals and/or enhancing irreversible binding (immobilization) of their products to soil is presently receiving considerable attention from the scientific community.
Access this article
Subscribe and save
- Get 10 units per month
- Download Article/Chapter or eBook
- 1 Unit = 1 Article or 1 Chapter
- Cancel anytime Subscribe now
Buy Now
Price excludes VAT (USA)
Tax calculation will be finalised during checkout.
Instant access to the full article PDF.
Similar content being viewed by others
Explore related subjects
Discover the latest articles, news and stories from top researchers in related subjects.
Author information
Authors and Affiliations
- Biotechnology Research Institute, National Research Council of Canada, 6100 Royalmount Ave, Montréal, Québec H4P 2R2, Canada e-mail: jalal.hawari@nrc.ca Fax: +1-514-4966265, , , , , , CA
J. Hawari, S. Beaudet & A. Halasz - Defence Research Establishment Valcartier, Department of National Defence, Val Belair, Québec G3J 1X5, Canada, , , , , , CA
S. Thiboutot & G. Ampleman
Authors
- J. Hawari
You can also search for this author inPubMed Google Scholar - S. Beaudet
You can also search for this author inPubMed Google Scholar - A. Halasz
You can also search for this author inPubMed Google Scholar - S. Thiboutot
You can also search for this author inPubMed Google Scholar - G. Ampleman
You can also search for this author inPubMed Google Scholar
Additional information
Received: 14 February 2000 / Received revision: 9 June 2000 / Accepted: 13 June 2000
Rights and permissions
About this article
Cite this article
Hawari, J., Beaudet, S., Halasz, A. et al. Microbial degradation of explosives: biotransformation versus mineralization.Appl Microbiol Biotechnol 54, 605–618 (2000). https://doi.org/10.1007/s002530000445
- Issue Date: November 2000
- DOI: https://doi.org/10.1007/s002530000445