Somnath Mallick, S. Chatterjee, T. Dutta
Jul 1, 2007
Citations
4
Influential Citations
123
Citations
Quality indicators
Journal
Microbiology
Abstract
Staphylococcus sp. strain PN/Y, capable of utilizing phenanthrene as a sole source of carbon and energy, was isolated from petroleum-contaminated soil. In the degradation of phenanthrene by strain PN/Y, various metabolites, isolated and identified by a combination of chromatographic and spectrometric analyses, revealed a novel phenanthrene assimilation pathway involving 2-hydroxy-1-naphthoic acid. Metabolism of phenanthrene was initiated by the dioxygenation on the 1,2-position of phenanthrene followed by meta-cleavage of phenanthrene-1,2-diol, leading to 2-hydroxy-1-naphthoic acid, which was then processed via a novel meta-cleavage pathway, leading to the formation of trans-2,3-dioxo-5-(2'-hydroxyphenyl)-pent-4-enoic acid and subsequently to salicylic acid. In the lower pathway, salicylic acid was transformed to catechol, which was then metabolized by catechol-2,3-dioxygenase to 2-hydroxymuconaldehyde acid, ultimately forming TCA cycle intermediates. The catabolic genes involved in phenanthrene degradation were found to be plasmid-encoded. This detailed study of polycyclic aromatic hydrocarbon (PAH) metabolism by a Gram-positive species involving a unique ring-cleavage dioxygenase in a novel phenanthrene degradation pathway provides a new insight into the microbial degradation of PAHs.