Biodegradation of the Insecticide N,N-Diethyl-m-Toluamide by Fungi: Identification and Toxicity of Metabolites

  • J. Seo
  • Y.-G. Lee
  • S.-D. Kim
  • C.-J. Cha
  • J.-H. Ahn
  • H.-G. HurEmail author


Fungi (Cunninghamella elegans ATCC 9245, Mucor ramannianus R-56, Aspergillus niger VKMF-1119, and Phanerochaete chrysosporium BKMF-1767) were tested to elucidate the biologic fate of the topical insect repellent N,N-diethyl-m-toluamide (DEET). The elution profile obtained from analysis by high-pressure liquid chromatography equipped with a reverse-phase C-18 column, showed that three peaks occurred after incubation of C. elegans, with which 1 mM DEET was combined as a final concentration. The peaks were not detected in the control experiments with either DEET alone or tested fungus alone. The metabolites produced by C. elegans exhibited a molecular mass of 207 with a fragment ion (m/z) at 135, a molecular mass of 179 with an m/z at 135, and a molecular mass of 163 with an m/z at 119, all of which correspond to N,N-diethyl-m-toluamide-N-oxide, N-ethyl-m-toluamide-N-oxide, and N-ethyl-m-toluamide, respectively. M. ramannianus R-56 also produced N, N-diethyl-m-toluamide-N-oxide and N-ethyl-m-toluamide but did not produce N-ethyl-m-toluamide-N-oxide. For the biologic toxicity test with DEET and its metabolites, the freshwater zooplankton Daphnia magna was used. The biologic sensitivity in decreasing order was DEET > N-ethyl-m-toluamide > N,N-diethyl-m-toluamide-N-oxide. Although DEET and its fungal metabolites showed relatively low mortality compared with other insecticides, the toxicity was increased at longer exposure periods. These are the first reports of the metabolism of DEET by fungi and of the biologic toxicity of DEET and its fungal metabolites to the freshwater zooplankton D. magna.


Phanerochaete Chrysosporium Deet Fungal Metabolite Biologic Toxicity Photo Diode Array 
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This work was supported by the Eco-Technopia project of the Ministry of Environment (Korean Government) and Grant No. 4-1-2 from the Sustainable Water Resources Research Center of the 21st-Century Frontier Rand program through the Water Reuse Technology Center at the Gwangju Institute of Science and Technology. The authors thank Drs. C. E. Cerniglia and I. A. Parshikov at the National Center for Toxicology Research, USFDA (Jefferson, AR) for their donation of the soil fungi used in this research.


  1. Cha, CJ, Doerge, DR, Cerniglia, CE 2001Biotransformation of malachite green by the fungus Cunninghamella elegansAppl Environ Microbiol6743584360CrossRefPubMedGoogle Scholar
  2. el Sayed, KA, Halim, AF, Zaghloul, AM, Dunbar, DC, McChesney, JD 2000Transformation of jervine by Cunninghamella elegans ATCC 9245Phytochemistry551922CrossRefPubMedGoogle Scholar
  3. Ferris, JP, Fasco, MJ, Stylianopoulou, FL, Jerina, DM, Daly, JW, Jeffrey, AM 1973Monooxygenase activity in Cunninghamella bainieri: Evidence for a fungal system similar to liver microsomesArch Biochem Biophys15697103CrossRefPubMedGoogle Scholar
  4. Ibrahim, ARS 2000Sulfation of naringenin by Cunninghamella elegansPhytochemistry53209212CrossRefPubMedGoogle Scholar
  5. Kolpin, DW, Furlong, ET, Meyer, MT, Thurman, EM, Zaugg, SD, Barber, LB,  et al. 2002Pharmaceuticals, hormones, and other organic wastewater contaminants in U.S. streams, 1999-2000: A national reconnaissanceEnviron Sci Technol361202 1211CrossRefPubMedGoogle Scholar
  6. Ma, H, Kim, SD, Cha, DK 1999Effect of kinetics of complexation by humic acid on toxicity of copper to Ceriodaphnia dubiaEnviron Toxicol Chem18828837CrossRefGoogle Scholar
  7. McCain, WC, Lee, R, Johnson, MS, Whaley, JE, Ferguson, JW, Beall, P,  et al. 1997Acute oral toxicity of pyridostigmine bromide, permenthrin, and DEET in the laboratory ratJ Toxicol Environ Health50113124CrossRefPubMedGoogle Scholar
  8. Moody, JD, Heinze, TM, Hansen, EB,Jr, Cerniglia, CE 2000aMetabolism of the ethanolamine-type antihistamine diphenhydramine (Benadryl) by the fungus Cunninghamella elegansAppl Microbiol Biotechnol53310315CrossRefGoogle Scholar
  9. Moody, JD, Zhang, D, Heinze, TM, Cerniglia, CE 2000bTransformation of amoxapine by Cunninghamella elegansAppl Environ Microbiol6636463649CrossRefGoogle Scholar
  10. Park, MK, Liu, KH, Lee, YH, Lee, YS, Hur, HG, Kim, JH 2002In vitro metabolism of ethaboxam by rat liver microsomesAgric Chem Biotechnol459498Google Scholar
  11. Park, MK, Liu, KH, Lim, Y, Lee, YH, Hur, HG, Kim, JH 2003Biotransformation of a fungicide ethaboxam by soil fungus Cunninghamella elegansJ Microbiol Biotechnol134349Google Scholar
  12. Pothuluri, JV, Freeman, JP, Heinze, TM, Beger, RD, Cerniglia, CE 2000Biotransformation of vinclozolin by the fungus Cunninghamella elegansJ Agric Food Chem4861386148CrossRefPubMedGoogle Scholar
  13. Qiu, H, McCall, JW, Jun, HW 1998Formulation of topical insect repellent N,N-diethyl-m-toluamide (DEET): Vehicle effects on DEET in vitro skin permeationInt J Pharm.163167176CrossRefGoogle Scholar
  14. Schoenig, GP, Osimitz, TG, Gabriel, KL, Hartnagel, R, Gill, MW, Goldenthal, EI 1999Evalutation of the chronic toxicity and oncogenicity of N,N-diethyl-m-toluamideToxicol Sci4799109CrossRefPubMedGoogle Scholar
  15. United States Environmental Protection Agency (1993) Method for measuring the acute toxicity of effluents and receiving waters to freshwater and marine organisms (EPA/600/4-90/027F). Cincinnati, OHGoogle Scholar
  16. United States Environmental Protection Agency (1998) Registration eligibility decision (RED) DEET (EPA738-R-98-010). Washington, DCGoogle Scholar
  17. Veltri, JC, Osimitz, TG, Bradford, DC 1994Retrospective analysis of calls of poison control centers resulting from exposure to the insect repellent N,N-diethyl-m-tolua-mide (DEET) from 1985 to 1989Clin Toxicol3217 30Google Scholar
  18. Zhang, D, Hansen, EB,Jr, Deck, J, Heinze, TM, Sutherland, JB, Cerniglia, CE 1996Fungal biotransformation of the antihistamine azatadine by Cunninghamella elegansAppl Environ Microbiol6234773479PubMedGoogle Scholar

Copyright information

© Springer Science+Business Media, Inc. 2005

Authors and Affiliations

  • J. Seo
    • 1
    • 2
  • Y.-G. Lee
    • 1
  • S.-D. Kim
    • 1
    • 2
  • C.-J. Cha
    • 3
  • J.-H. Ahn
    • 4
  • H.-G. Hur
    • 1
    • 2
    Email author
  1. 1.Department of Environmental Science and EngineeringGwangju Institute of Science and TechnologyKorea
  2. 2.Water Reuse Technology CenterGwangju Institute of Science and TechnologyKorea
  3. 3.Department of Biotechnology, College of Industrial ScienceChung-Ang UniversityAnseongKorea
  4. 4.Bio/Molecular Informatics CenterKonkuk UniversitySeoulKorea

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