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

 Previous Article  |  Next Article 

Applied and Environmental Microbiology, July 2002, p. 3478-3485, Vol. 68, No. 7
0099-2240/02/$04.00+0     DOI: 10.1128/AEM.68.7.3478-3485.2002
Copyright © 2002, American Society for Microbiology. All Rights Reserved.

Growth in Coculture Stimulates Metabolism of the Phenylurea Herbicide Isoproturon by Sphingomonas sp. Strain SRS2

Department of Geochemistry, Geological Survey of Denmark and Greenland (GEUS), Copenhagen, Denmark,¹ Department of Environmental Hydrology and Microbiology, Ben Gurion University of the Negev, Jacob Blaustein Institute for Desert Research, Sede-Boker, Israel²

Received 7 January 2002/ Accepted 25 April 2002

Metabolism of the phenylurea herbicide isoproturon by Sphingomonas sp. strain SRS2 was significantly enhanced when the strain was grown in coculture with a soil bacterium (designated strain SRS1). Both members of this consortium were isolated from a highly enriched isoproturon-degrading culture derived from an agricultural soil previously treated regularly with the herbicide. Based on analysis of the 16S rRNA gene, strain SRS1 was assigned to the ß-subdivision of the proteobacteria and probably represents a new genus. Strain SRS1 was unable to degrade either isoproturon or its known metabolites 3-(4-isopropylphenyl)-1-methylurea, 3-(4-isopropylphenyl)-urea, or 4-isopropyl-aniline. Pure culture studies indicate that Sphingomonas sp. SRS2 is auxotrophic and requires components supplied by association with other soil bacteria. A specific mixture of amino acids appeared to meet these requirements, and it was shown that methionine was essential for Sphingomonas sp. SRS2. This suggests that strain SRS1 supplies amino acids to Sphingomonas sp. SRS2, thereby leading to rapid metabolism of ¹⁴C-labeled isoproturon to ¹⁴CO₂ and corresponding growth of strain SRS2. Proliferation of strain SRS1 suggests that isoproturon metabolism by Sphingomonas sp. SRS2 provides unknown metabolites or cell debris that supports growth of strain SRS1. The role of strain SRS1 in the consortium was not ubiquitous among soil bacteria; however, the indigenous soil microflora and some strains from culture collections also stimulate isoproturon metabolism by Sphingomonas sp. strain SRS2 to a similar extent.

This article has been cited by other articles:

• Barreiros, L., Fernandes, A., Ferreira, A. C. S., Pereira, H., Bastos, M. M. S. M., Manaia, C. M., Nunes, O. C. (2008). New insights into a bacterial metabolic and detoxifying association responsible for the mineralization of the thiocarbamate herbicide molinate. Microbiology 154: 1038-1046 [Abstract] [Full Text]  
• Sorensen, S. R., Rasmussen, J., Jacobsen, C. S., Jacobsen, O. S., Juhler, R. K., Aamand, J. (2005). Elucidating the Key Member of a Linuron-Mineralizing Bacterial Community by PCR and Reverse Transcription-PCR Denaturing Gradient Gel Electrophoresis 16S rRNA Gene Fingerprinting and Cultivation. Appl. Environ. Microbiol. 71: 4144-4148 [Abstract] [Full Text]  
• Dejonghe, W., Berteloot, E., Goris, J., Boon, N., Crul, K., Maertens, S., Hofte, M., De Vos, P., Verstraete, W., Top, E. M. (2003). Synergistic Degradation of Linuron by a Bacterial Consortium and Isolation of a Single Linuron-Degrading Variovorax Strain. Appl. Environ. Microbiol. 69: 1532-1541 [Abstract] [Full Text]