Archives of Environmental Contamination and Toxicology

, Volume 48, Issue 3, pp 323–328

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. Hur
Article

DOI: 10.1007/s00244-004-0029-9

Cite this article as:
Seo, J., Lee, YG., Kim, SD. et al. Arch Environ Contam Toxicol (2005) 48: 323. doi:10.1007/s00244-004-0029-9

Abstract

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.

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
  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