Previous Article | Next Article ![]()
Applied and Environmental Microbiology, December 2003, p. 7108-7115, Vol. 69, No. 12
0099-2240/03/$08.00+0 DOI: 10.1128/AEM.69.12.7108-7115.2003
Copyright © 2003, American
Society for
Microbiology. All Rights Reserved.
Laboratorio de Microbiología, Departamento de Genética Molecular y Microbiologia, and Center for Advanced Studies in Ecology and Biodiversity, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago,1 Departamento de Microbiología, Facultad de Ciencias Biológicas,Universidad de Concepción, Concepción,Chile2
Received 3 June 2003/ Accepted 9 September 2003
2,4,6-Trichlorophenol (2,4,6-TCP) is a hazardous pollutant. Several aerobic bacteria are known to degrade this compound. One of these, Ralstonia eutropha JMP134(pJP4), a well-known, versatile chloroaromatic compound degrader, is able to grow in 2,4,6-TCP by converting it to 2,6-dichlorohydroquinone, 6-chlorohydroxyquinol, 2-chloromaleylacetate, maleylacetate, and ß-ketoadipate. Three enzyme activities encoded by tcp genes, 2,4,6-TCP monooxygenase (tcpA), 6-chlorohydroxyquinol 1,2-dioxygenase (tcpC), and maleylacetate reductase (tcpD), are involved in this catabolic pathway. Here we provide evidence that all these tcp genes are clustered in the R. eutropha JMP134(pJP4) chromosome, forming the putative catabolic operon tcpRXABCYD. We studied the presence of tcp-like gene sequences in several other 2,4,6-TCP-degrading bacterial strains and found two types of strains. One type includes strains belonging to the Ralstonia genus and possessing a set of tcp-like genes, which efficiently degrade 2,4,6-TCP and therefore grow in liquid cultures containing this chlorophenol as a sole carbon source. The other type includes strains belonging to the genera Pseudomonas, Sphingomonas, or Sphingopixis, which do not have tcp-like gene sequences and degrade this pollutant less efficiently and which therefore grow only as small colonies on plates with 2,4,6-TCP. Other than strain JMP134, none of the bacterial strains whose genomes have been sequenced possesses a full set of tcp-like gene sequences.
This article has been cited by other articles:
| J. Bacteriol. | Microbiol. Mol. Biol. Rev. | Eukaryot. Cell | All ASM Journals |
|---|