Deep-Sea Oil Plume Enriches Indigenous Oil-Degrading Bacteria

TLDR

The fate of the Deepwater Horizon oil spill in the Gulf of Mexico remains unclear due to its depth and scale. The dispersed oil plume stimulated deep‑sea γ‑Proteobacteria with hydrocarbon‑degrading genes that correlated with contaminant levels, and incubation experiments showed rapid biodegradation at 5 °C, indicating potential for intrinsic bioremediation without major oxygen depletion.

Abstract

The biological effects and expected fate of the vast amount of oil in the Gulf of Mexico from the Deepwater Horizon blowout are unknown owing to the depth and magnitude of this event. Here, we report that the dispersed hydrocarbon plume stimulated deep-sea indigenous γ-Proteobacteria that are closely related to known petroleum degraders. Hydrocarbon-degrading genes coincided with the concentration of various oil contaminants. Changes in hydrocarbon composition with distance from the source and incubation experiments with environmental isolates demonstrated faster-than-expected hydrocarbon biodegradation rates at 5°C. Based on these results, the potential exists for intrinsic bioremediation of the oil plume in the deep-water column without substantial oxygen drawdown.