Identification of a homogentisate-1,2-dioxygenase gene in the fungus Exophiala lecanii-corni: analysis and implications.


Journal Article

Exophiala lecanii-corni is a dimorphic fungus capable of degrading several volatile organic compounds (VOCs) including ethylbenzene, which has been classified as a hazardous air pollutant by the Environmental Protection Agency. In contrast to bacterial species, little is known about the mechanisms of fungal degradation of VOCs. The results described herein suggest a potential pathway for ethylbenzene degradation in E. lecanii-corni via styrene, phenylacetate and homogentisate. Consistent with this proposed pathway, a full-length homogentisate-1,2-dioxygenase gene (ElHDO) has been identified, cloned and sequenced. The nucleotide sequence of ElHDO consists of a 1,452-bp open reading frame encoding a protein with 484 amino acids. The expression of the gene product increases when grown on ethylbenzene, further suggesting that it could be involved in ethylbenzene degradation and may be responsible for the aromatic ring cleavage reaction. In addition, a 907-bp fragment isolated upstream from this gene shares 78% sequence identity at the amino acid level with the amino acid sequences of two fungal phenylacetate hydroxylase genes. This observation suggests that the genes responsible for ethylbenzene degradation may be clustered. This research constitutes the first step towards a better understanding of ethylbenzene degradation in E. lecanii-corni.

Full Text

Duke Authors

Cited Authors

  • Gunsch, CK; Cheng, Q; Kinney, KA; Szaniszlo, PJ; Whitman, CP

Published Date

  • August 2005

Published In

Volume / Issue

  • 68 / 3

Start / End Page

  • 405 - 411

PubMed ID

  • 15731901

Pubmed Central ID

  • 15731901

Electronic International Standard Serial Number (EISSN)

  • 1432-0614

International Standard Serial Number (ISSN)

  • 0175-7598

Digital Object Identifier (DOI)

  • 10.1007/s00253-005-1899-0


  • eng