Scientists find new microbe in Macondo oil spill

US Department of Energy Lawrence Berkeley National Laboratory scientists found microbes degraded oil in deepwater much faster than anticipated, and this degradation appears to take place without a significant level of oxygen depletion.

That is among the most positive findings following the massive oil spill from BP PLC’s Macondo well off Louisiana in 5,000 ft of water. Berkeley Lab scientists found the presence of various hydrocarbon degraders, adding that the dominant microbe in the dispersed Macondo oil was a new, unclassified species.

The existence of oil at extreme water depths posed numerous questions. BP deployed chemical dispersants at the wellhead, creating tiny petroleum particles in efforts to prevent oil from reaching the gulf’s surface.

The environmental effects of dispersants have been studied in surface water applications for years, but their potential effect on the deepwater gulf marine ecosystem was unknown.

Terry Hazen, a Berkeley Lab microbial ecologist, said findings “suggest that a great potential for intrinsic bioremediation of oil plumes exists in the deep sea.” The research done by Hazen and his colleagues was reported in Science (Aug. 26 online) in a paper entitled “Deep-sea oil plume enriches indigenous oil-degrading bacteria.”

The influx of oil “profoundly altered the microbial community” by stimulating psychrophilic (cold temperature) gamma-proteobacteria closely related to known petroleum-degrading microbes.

Psychrophilic petroleum degraders contributed to the rapid decline of the Macondo oil, he said. Analysis of changes in the crude oil composition indicated faster-than-expected biodegradation rates with the half-life of the oil’s alkanes ranging from 1.2 to 6.1 days.