Research suggests role of bacteria has been underestimated
By Summit Voice
FRISCO — Nearly three years after the Deepwater Horizon drill rig exploded and the busted Macondo Well spewed millions of gallons of crude into the Gulf of Mexico, scientists are still trying to figure out to what happened to all the oil.
Only a tiny amount was captured or burned at the surface, and vast quantity — nobody knows exactly how much — was “dispersed” with chemicals injected directly into the stream of oil streaming out of the broken pipes, but a surprisingly large percentage of the oil may have been broken down by microbes.
Some of the oil settled to the seafloor, damaging coral miles from the site of the disaster. There’s also evidence that the oil damaged Gulf of Mexico oysters growing in coastal areas, and sickened dolphins in Barataria Bay. And in Florida, researchers found remnants of the oil lingering in “scary high” concentrations in the splash zone along Gulf beaches.
Hazen and his research team used a powerful new approach for identifying microbes in the environment to discover previously unknown and naturally occurring bacteria that consume and break down crude oil. They concluded that 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,” Hazen said. “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 six days … “The Deepwater Horizon oil provided a new source of nutrients in the deepest waters,” he said.
Rather than culturing the microbes in a lab, the researchers combined genetic data and other analyses of the DNA, proteins and other footprints of bacteria to provide a more detailed picture of microbial life in the water.
Their findings suggest that a great potential for intrinsic bioremediation of oil plumes exists in the deep sea and other environs in the Gulf of Mexico. Oil-eating bacteria are natural inhabitants of the Gulf because of the constant supply of oil as food.
“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 break down 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.”
Hazen recently presented his Deepwater Horizon disaster research findings at the 245th National Meeting and Exposition of the American Chemical Society, the world’s largest scientific society.