Microbial Degradation of Pesticides
Abstract
The pathway of degradation of one organophosphorus insecticide, Dichlorvos, was studied in detail. A microbial enrichment containing principally two pseudomonads and a bacillus, when incubated in a salts solution containing a vitamin supplement and 250 microgram/milliliter Dichlorvos as sole carbon source, could partially degrade the insecticide. At the end of 7 days incubation, much of the parent molecule was still present but biologically formed metabolites were also noted by TLC, GLC, and mass spectral analyses. The presence of dichloroethanol was confirmed, and evidence was also obtained for the presence of 1,1-dichloroethyl acetate, suggesting a mechanism of cleavage whereby the dichlorovinyl leaving group of the molecule is cleaved from the parent molecule. Whether cleavage was chemical, biological or both was not determined. Inorganic phosphate was formed in increasing amounts in a 4-day incubation period, especially in treatments containing a second more utilizable carbon source, implying a cometabolic route for the degradation of Dichlorvos. Evidence for biological demethylation was also obtained. The results provide evidence for a microbial role in the transformation in conjunction with chemical hydrolysis of Dichlorvos. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Nov 30, 1981
- Accession Number
- ADA108872
Entities
People
- M. Alexander
Organizations
- Cornell University