Detection of mega plasmid from polycyclic aromatic hydrocarbon-degrading Sphingomonas sp. strain KS14.

Polycyclic aromatic hydrocarbon (PAH) degrading Sphingomonas sp. strain KS14 was isolated from soil. Strain KS14 was able to utilize phenanthrene and naphthalene as sole source of carbon and energy, and mineralize phenanthrene to carbon dioxide. Strain KS14 cometabolically degraded pyrene using phenanthrene as secondary growth substrate. A large degradative plasmid (>500 kb) was detected from the strain KS14. This study suggests that this mega plasmid could be responsible for the degradation of PAH by strain KS14.