Sphingomonas yanoikuyae B1 is extremely versatile in its catabolic ability. An insertional mutant strain, S. yanoikuyae EK504, which is unable to grow on naphthalene due to the loss of 2-hydroxychromene-2-carboxylate isomerase activity, was utilized to investigate the role of this enzyme in the degradation of anthracene by S. yanoikuyae B1. Although EK504 is unable to grow on anthracene, this strain could transform anthracene to some extent. A metabolite in the degradation of anthracene by EK504 was isolated by high- pressure liquid chromatography (HPLC) and was identified as 6,7-benzocoumarin by UV-visible, gas-chromatographic, HPLC/mass-spectrometric, and 1H nuclear magnetic resonance spectral techniques. The identification of 6,7- benzocoumarin provides direct chemical and genetic evidence for the involvement of nahD in the degradation of anthracene by S. yanoikuyae B1.
Bibliographical noteFunding Information:
This research was supported in part by an appointment to the Postgraduate Research Program at the National Center for Toxicological Research administered by the Oak Ridge Institute for Science and Education through an interagency agreement between the U.S. Department of Energy and the U.S. Food and Drug Administration and by a grant from the Electric Power Research Institute. G.J.Z. is the recipient of a Young Investigator Award from the National Science Foundation. We thank Kay L. Shuttleworth and Jack Lay for critical reading of the manuscript and Kim Otwell for graphic illustrations.
All Science Journal Classification (ASJC) codes
- Molecular Biology