16S metagenomic analysis reveals adaptability of a mixed-PAH-degrading consortium isolated from crude oil-contaminated seawater to changing environmental conditions

摘要

A bacterial consortium, named SWO, was enriched from crude oil-contaminated seawater from Phrao Bay in Rayong Province, Thailand, after a large oil spill in 2013. The bacterial consortium degraded a polycyclic aromatic hydrocarbon (PAH) mixture consisting of phenanthrene, anthracene, fluoranthene, and pyrene (50 mg L−1each) by approximately 73%, 69%, 52%, and 48%, respectively, within 21 days. This consortium exhibited excellent adaptation to a wide range of environmental conditions. It could degrade a mixture of four PAHs under a range of pH values (4.0–9.0), temperatures (25 °C–37 °C), and salinities (0–10 g L−1with NaCl). In addition, this consortium degraded 20–30% of benzo[a]pyrene and perylene (10 mg L−1each), high molecular weight PAHs, in the presence of other PAHs within 35 days, and degraded 40% of 2% (v/v) crude oil within 20 days. The 16S rRNA gene amplicon sequencing analysis demonstrated thatPseudomonasandMethylophagawere the dominant genera of consortium SWO in almost all treatments, whilePseudidiomarina,ThalassospiraandAlcanivoraxwere predominant under higher salt concentrations. Moreover,PseudomonasandAlcanivoraxwere dominant in the crude oil-degradation treatment. Our results suggest that the consortium SWO maintained its biodegradation ability by altering the bacterial community profile upon encountering changes in the environmental conditions.