This Article
Right arrow Full Text
Right arrow Full Text (PDF)
Right arrow Supplemental material
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrowReprints and Permissions
Right arrow Copyright Information
Right arrow Books from ASM Press
Right arrow MicrobeWorld
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Witzig, R.
Right arrow Articles by Pieper, D. H.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Witzig, R.
Right arrow Articles by Pieper, D. H.
Agricola
Right arrow Articles by Witzig, R.
Right arrow Articles by Pieper, D. H.

 Previous Article  |  Next Article 

Applied and Environmental Microbiology, May 2006, p. 3504-3514, Vol. 72, No. 5
0099-2240/06/$08.00+0     doi:10.1128/AEM.72.5.3504-3514.2006
Copyright © 2006, American Society for Microbiology. All Rights Reserved.

Assessment of Toluene/Biphenyl Dioxygenase Gene Diversity in Benzene-Polluted Soils: Links between Benzene Biodegradation and Genes Similar to Those Encoding Isopropylbenzene Dioxygenases{dagger}

Robert Witzig,1 Howard Junca,1 Hans-Jürgen Hecht,2 and Dietmar H. Pieper1*

Department of Environmental Microbiology,1 Division of Structural Biology, GBF—German Research Centre for Biotechnology, Mascheroder Weg 1, D-38124 Braunschweig, Germany2

Received 9 November 2005/ Accepted 13 March 2006

The PCR-single-strand conformation polymorphism (SSCP) technique was used to assess the diversity and distribution of Rieske nonheme iron oxygenases of the toluene/biphenyl subfamily in soil DNA and bacterial isolates recovered from sites contaminated with benzene, toluene, ethylbenzene, and xylenes (BTEX). The central cores of genes encoding the catalytic {alpha} subunits were targeted, since they are responsible for the substrate specificities of these enzymes. SSCP functional genotype fingerprinting revealed a substantial diversity of oxygenase genes in three differently BTEX-contaminated soil samples, and sequence analysis indicated that in both the soil DNA and the bacterial isolates, genes for oxygenases related to the isopropylbenzene (cumene) dioxygenase branch of the toluene/biphenyl oxygenase subfamily were predominant among the detectable genotypes. The peptide sequences of the two most abundant {alpha} subunit sequence types differed by only five amino acids (residues 258, 286, 288, 289, and 321 according to numbering in cumene dioxygenase {alpha} subunit CumA1 of Pseudomonas fluorescens IP01). However, a strong correlation between sequence type and substrate utilization pattern was observed in isolates harboring these genes. Two of these residues were located at positions contributing, according to the resolved crystal structure of cumene dioxygenase from Pseudomonas fluorescens IP01, to the inner surface of the substrate-binding pocket. Isolates containing an {alpha} subunit with isoleucine and leucine at positions 288 and 321, respectively, were capable of degrading benzene and toluene, whereas isolates containing two methionine substitutions were found to be incapable of degrading toluene, indicating that the more bulky methionine residues significantly narrowed the available space within the substrate-binding pocket.

* Corresponding author. Mailing address: Department of Environmental Microbiology, GBF—German Research Centre for Biotechnology, Mascheroder Weg 1, D-38124 Braunschweig, Germany. Phone: (49) 531-6181467. Fax: (49) 531-6181411. E-mail: dpi{at}gbf.de.

{dagger} Supplemental material for this article may be found at http://aem.asm.org/.

Applied and Environmental Microbiology, May 2006, p. 3504-3514, Vol. 72, No. 5
0099-2240/06/$08.00+0     doi:10.1128/AEM.72.5.3504-3514.2006
Copyright © 2006, American Society for Microbiology. All Rights Reserved.



This article has been cited by other articles:

  • Weelink, S. A. B., Tan, N. C. G., ten Broeke, H., van den Kieboom, C., van Doesburg, W., Langenhoff, A. A. M., Gerritse, J., Junca, H., Stams, A. J. M. (2008). Isolation and Characterization of Alicycliphilus denitrificans Strain BC, Which Grows on Benzene with Chlorate as the Electron Acceptor. Appl. Environ. Microbiol. 74: 6672-6681 [Abstract] [Full Text]  
  • de Carcer, D. A., Martin, M., Karlson, U., Rivilla, R. (2007). Changes in Bacterial Populations and in Biphenyl Dioxygenase Gene Diversity in a Polychlorinated Biphenyl-Polluted Soil after Introduction of Willow Trees for Rhizoremediation. Appl. Environ. Microbiol. 73: 6224-6232 [Abstract] [Full Text]  
  • Caballero-Mellado, J., Onofre-Lemus, J., Estrada-de los Santos, P., Martinez-Aguilar, L. (2007). The Tomato Rhizosphere, an Environment Rich in Nitrogen-Fixing Burkholderia Species with Capabilities of Interest for Agriculture and Bioremediation. Appl. Environ. Microbiol. 73: 5308-5319 [Abstract] [Full Text]  


Copyright © 2009 by the American Society for Microbiology.   For an alternate route to Journals.ASM.org, visit: http://intl-journals.asm.org | More Info»