A novel degradation pathway in the assimilation of phenanthrene by Staphylococcus sp. strain PN/Y via meta-cleavage of 2-hydroxy-1-naphthoic acid: formation of trans-2,3-dioxo-5-(2'-hydroxyphenyl)-pent-4-enoic acid.
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.
Mallick
Somnath
S
Department of Microbiology, Bose Institute, Kolkata 700054, India.
Chatterjee
Subhankar
S
Department of Microbiology, Bose Institute, Kolkata 700054, India.
Dutta
Tapan K
TK
Department of Microbiology, Bose Institute, Kolkata 700054, India.
D001673:Biodegradation, Environmental; D008969:Molecular Sequence Data; D009284:Naphthols / Q000737:chemistry / Q000378:metabolism*; D010616:Phenanthrenes / Q000737:chemistry / Q000378:metabolism*; D011084:Polycyclic Aromatic Hydrocarbons / Q000378:metabolism; D013210:Staphylococcus / Q000302:isolation & purification / Q000378:metabolism*
D009284:Naphthols; D010616:Phenanthrenes; D011084:Polycyclic Aromatic Hydrocarbons