April 9, 2013
Gulf Of Mexico Bacteria Found To Break Down And Consume Crude Oil
Brett Smith for redOrbit.com - Your Universe Online
When it happened in 2010, the Deepwater Horizon oil spill released 210 million gallons of oil into the Gulf of Mexico and was described as one of the greatest man-made ecological disasters to ever impact the region.
According to the Department of Energy´s (DoE) Terry C. Hazen, researchers found previously unknown and naturally occurring Gulf bacteria that consume and break down crude oil.
"The Deepwater Horizon oil provided a new source of nutrients in the deepest waters," said Hazen, a professor at the University of Tennessee (UT) in Knoxville. "With more food present in the water, there was a population explosion among those bacteria already adapted to using oil as a food source. It was surprising how fast they consumed the oil.”
“In some locations, it took only one day for them to reduce a gallon of oil to a half gallon. In others, the half-life for a given quantity of spilled oil was 6 days,” Hazen said in a statement. “This data suggests that a great potential for intrinsic bioremediation of oil plumes exists in the deep sea and other environs in the Gulf of Mexico."
To discover these oil-eating bacteria, the research team used a groundbreaking new approach. Instead of culturing water samples in petri dishes, the team used genetic and other analyses of the DNA proteins in the water, referred to as “ecogenomics,” to generate a thorough picture of microbial life in their samples.
Hazen told BBC News that the cleansing of the Gulf was primarily performed by methanotroph bacteria, which fed on the methane that was also released during the oil spill. This abrupt and fortunate release of methane spurred the methanotroph populations within the Gulf.
"All of a sudden the [methanotroph populations] go up to really high densities and they're fat and happy - and then [the methane is] gone." he said. "At that point, they degrade anything else that's there fortuitously, and they'll degrade it down below what would be usable as a carbon and energy source - so it's really sort of a 'deep-cleaning' effect."
Hazen suggested that the natural mechanisms within the Gulf may be enough to combat future oil spills and human clean-up efforts should be calibrated with the activity of methanotrophs in mind.
"The bottom line from this research may be that the Gulf of Mexico is more resilient and better able to recover from oil spills than anyone thought," Hazen said. "It shows that we may not need the kinds of heroic measures proposed after the Deepwater Horizon spill, like adding nutrients to speed up the growth of bacteria that breakdown oil, or using genetically engineered bacteria. The Gulf has a broad base of natural bacteria, and they respond to the presence of oil by multiplying quite rapidly."
Along with the ACS meeting, legal action against BP took a significant step forward this week in New Orleans as the oil company called its first witness to the stand in its trial defense.