Identification of novel metabolites in the degradation of phenanthrene by Sphingomonas sp strain P2

Sphingomonas sp. strain P2, which is capable of utilizing phenanthrene as a sole carbon and energy source, was isolated from petroleum-contaminated soil in Thailand. Gas chromatography-mass spectrometry and H-1 and C-13 nuclear magnetic resonance analyses revealed two novel metabolites from the phenanthrene degradation pathway. One was identified as 5,6-benzocoumarin, which was derived by dioxygenation at the 1- and 2-positions of phenanthrene, and the other was determined to be 1,5-dihydroxy-2-naphthoic acid. Other metabolites from phenanthrene degradation were identified as 7,8-benzocoumarin, 1-hydroxy-2-naphthoic acid and coumarin. From these results. it is suggested that strain P2 call degrade phenanthrene via dioxygenation at both 1.2- and 3,4-positions followed by meta-cleavage. (C) 2000 Federation of European Microbiological Societies. Published by Elsevier Science B.V. All rights reserved.