Journal article
Transformation of the herbicide 2,6-dichlorobenzonitrile to the persistent metabolite 2,6-dichlorobenzamide (BAM) by soil bacteria known to harbour nitrile hydratase or nitrilase
Department of Geochemistry, Geological Survey of Denmark and Greenland, 1350, Copenhagen, Denmark, msh@geus.dk1
In soil the herbicide 2,6-dichlorobenzonitrile (dichlobenil) is degraded to the persistent metabolite 2,6-dichlorobenzamide (BAM) which has been detected in 19% of samples taken from Danish groundwater. We tested if common soil bacteria harbouring nitrile-degrading enzymes, nitrile hydratases or nitrilases, were able to degrade dichlobenil in vitro.
We showed that several strains degraded dichlobenil stoichiometrically to BAM in 1.5-6.0 days; formation of the amide intermediate thus showed nitrile hydratase rather than nitrilase activity, which would result in formation of 2,6-dichlorobenzoic acid. The non-halogenated analogue benzonitrile was also degraded, but here the benzamide intermediate accumulated only transiently showing nitrile hydratase followed by amidase activity.
We conclude that a potential for dichlobenil degradation to BAM is found commonly in soil bacteria, whereas further degradation of the BAM intermediate could not be demonstrated.
Language: | English |
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Publisher: | Kluwer Academic Publishers |
Year: | 2006 |
Pages: | 503-10 |
ISSN: | 15729729 and 09239820 |
Types: | Journal article |
DOI: | 10.1007/s10532-005-9021-y |
ORCIDs: | Sørensen, Jan and Hansen, Hans Christian B |
2,6-dichlorobenzamide Amidase, BAM, dichlobenil, nitrilase, nitrile hydratase Aminohydrolases Ammonium Chloride Benzamides Biodegradation, Environmental Environment Geochemistry Herbicides Hydro-Lyases Nitriles Nitrogen Pseudomonas Rhizobium Rhodococcus Soil Microbiology Soil Science & Conservation Terrestrial Pollution Waste Management/Waste Technology Waste Water Technology / Water Pollution Control / Water Management / Aquatic Pollution dichlobanil nitrilase nitrile hydratase