Previous Article | Next Article ![]()
Appl. Environ. Microbiol., 01 1996, 230-236, Vol 62, No. 1
AK Goyal and GJ Zylstra
Three strains of Comamonas testosteroni were isolated from river sediment
for the ability to degrade phenanthrene; two of the strains also grew on
naphthalene, and one strain also grew on anthracene. The homology of the
genes for polycyclic aromatic hydrocarbon degradation in these strains to
the classical genes (nah) for naphthalene degradation from Pseudomonas
putida NCIB 9816-4 was determined. The three C. testosteroni strains showed
no homology to the nah gene probe even under low-stringency conditions. The
genes for naphthalene and phenanthrene degradation were cloned from one of
the three C. testosteroni strains. Two cosmid clones expressing polycyclic
aromatic hydrocarbon dioxygenase activity were identified from a library
prepared with genomic DNA from C. testosteroni GZ39. The genes coding for
the first two enzymes in the catabolic pathway, phenanthrene dioxygenase
and cis-phenanthrene dihydrodiol dehydrogenase, were localized to a 5.4-kb
NcoI-PstI fragment by subcloning and gene expression experiments. Further
subcloning and analysis revealed a novel organization of the genes, with
the gene for cis-phenanthrene dihydrodiol dehydrogenase located between the
genes for the individual phenanthrene dioxygenase components. A Southern
blot with the cloned genes from C. testosteroni GZ39 confirmed that these
genes are distinct from those found in P. putida NCIB 9816-4. Southern
blots also demonstrated that C. testosteroni GZ38A possesses genes for
phenanthrene degradation that are similar to those cloned from C.
testosteroni GZ39. However, C. testosteroni GZ42 possesses genes for
phenanthrene degradation that are not homologous to those cloned from C.
testosteroni GZ39. This suggests that there are at least two different sets
of genes for the degradation of phenanthrene among the three C.
testosteroni strains.
Copyright © 1996, American Society for Microbiology
Molecular cloning of novel genes for polycyclic aromatic hydrocarbon degradation from Comamonas testosteroni GZ39
Center for Agricultural Molecular Biology, Cook College, Rutgers University, New Brunswick, New Jersey 08903-0231, USA.
This article has been cited by other articles:
| J. Bacteriol. | Microbiol. Mol. Biol. Rev. | Eukaryot. Cell | All ASM Journals |
|---|