In an article published in Science, Terry C. Hazen, the chief microbiologist at the Department of Energy's Lawrence Berkeley National Laboratory, reports that oil-eating bacteria have largely consumed the deep-sea plume of dispersed oil fouling the Gulf of Mexico.  Many feared the dispersed plume would devastate the marine ecology in the gulf because many oil-eating bacteria consume oxygen as well as hydrocarbons - a process that could produce "dead zones". But Hazen and his lab colleagues report that the microbes devour the microscopic droplets with far less depletion of oxygen than other oil-eating bacteria.

The biological effects and expected fate of the vast amount of oil in the Gulf of Mexico from the Deepwater Horizon blowout are unknown due to the depth and magnitude of this event. Here, we report that the dispersed hydrocarbon plume stimulated deep-sea indigenous -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 demonstrate 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.

Access the abstract and article via ScienceXpress.

Contaminated Land Bulletin feature article about making remediation more sustainable – even if it means rethinking risk assessment.