Identification of a putative novel polycyclic aromatic hydrocarbon-biodegrading gene cluster in a marine <i>Roseobacteraceae</i> bacterium <i>Sagittula</i> sp. MA-2

The ocean is often characterized as the terminal destination for persistent polycyclic aromatic hydrocarbon (PAH) environmental pollutants; however, the ability to biodegrade PAHs and the corresponding enzymes conserved among marine bacteria are less understood compared to their terrestrial counterparts. A marine bacterial isolate, <i>Sagittula</i> sp. strain MA-2, belonging to the family <i>Roseobacteraceae</i>-a widely distributed and physiologically diverse marine bacterial group-was found to possess a functional gene cluster encoding enzymes potentially responsible for PAH biodegradation in its genome and exhibit the ability to biodegrade the three-ring PAH, phenanthrene. Intriguingly, gene clusters potentially homologous to this cluster were also distributed broadly across genomes from different <i>Roseobacteraceae</i> genera in public databases, which has not been previously investigated. The knowledge provided here expands our understanding of the physiology of <i>Roseobacteraceae</i> and may be applied to explore biotechnologically useful bacteria that contribute to the remediation of polluted marine environments or high-salinity wastewater.