Role for Microbes in Coping with Gulf Oil Spill
Amid anguish and anger over the massive oil spill in the Gulf of Mexico- particularly its destructive impact on that ecosystem-indigenous microorganisms will slowly but relentlessly play a major role in degrading much of that oil and helping to restore the equilibrium of that region, according to Jay Grimes of the University of Southern Mississippi in Hattiesburg and Ronald Atlas of the University of Louisville in Louisville, Kentucky, who spoke during a special session about the oil spill during the 110th ASM General Meeting last May in San Diego.
"Microorganisms consume many but not all the components in crude oil, but it's not an instantaneous process," Atlas says. "However, we're better off to clean it up physically than waiting for the microbes." In general, the hydrocarbon fractions in oil are degraded to carbon dioxide and water, while producing proteins and other macromolecules for the organisms. Less in the way ofmicrobial decomposition happens to the more polar fractions in crude oil. And the tars in oils tend to deposit, much like asphalt, along the ocean floor or on beaches.
One proven way to accelerate microbial action is to add fertilizer to provide oil-decomposing species and consortia with a better balance of nutrients, Atlas says. For the Gulf spill, he recommends adding fertilizers when oil comes onshore and "sooner, rather than later." Typically, there is a "burst" in activity and a sharp rise in populations of hydrocarbon- degrading microorganisms, temporarily reducing the local diversity of microbial populations.
Dispersants can help speed these degradative processes by making the crude oil more accessible to the microorganisms, according to Atlas. However, those dispersants, whose use is generally limited to oil floating on open waters, can damage other species, including fish and birds. Thus, he calls dispersants a "two-edged sword." Not a great deal is known about the toxicology of oil-dispersant mixtures, Grimes says, noting that a colleagues of his recently began to look systematically at the chronic effects of this combination on several representative species of fish and shellfish. "There soon may be serious federal money available for more studies," he notes.
Despite interest in inoculating microorganisms, including those specially selected or genetically engineered to degrade crude oil, there is little to suggest that they could outperform indigenous microbes, Grimes says. Adds Atlas, "I gave up looking for such miracle ‘bugs' years ago."
Amid anguish and anger over the massive oil spill in the Gulf of Mexico- particularly its destructive impact on that ecosystem-indigenous microorganisms will slowly but relentlessly play a major role in degrading much of that oil and helping to restore the equilibrium of that region, according to Jay Grimes of the University of Southern Mississippi in Hattiesburg and Ronald Atlas of the University of Louisville in Louisville, Kentucky, who spoke during a special session about the oil spill during the 110th ASM General Meeting last May in San Diego.
"Microorganisms consume many but not all the components in crude oil, but it's not an instantaneous process," Atlas says. "However, we're better off to clean it up physically than waiting for the microbes." In general, the hydrocarbon fractions in oil are degraded to carbon dioxide and water, while producing proteins and other macromolecules for the organisms. Less in the way ofmicrobial decomposition happens to the more polar fractions in crude oil. And the tars in oils tend to deposit, much like asphalt, along the ocean floor or on beaches.
One proven way to accelerate microbial action is to add fertilizer to provide oil-decomposing species and consortia with a better balance of nutrients, Atlas says. For the Gulf spill, he recommends adding fertilizers when oil comes onshore and "sooner, rather than later." Typically, there is a "burst" in activity and a sharp rise in populations of hydrocarbon- degrading microorganisms, temporarily reducing the local diversity of microbial populations.
Dispersants can help speed these degradative processes by making the crude oil more accessible to the microorganisms, according to Atlas. However, those dispersants, whose use is generally limited to oil floating on open waters, can damage other species, including fish and birds. Thus, he calls dispersants a "two-edged sword." Not a great deal is known about the toxicology of oil-dispersant mixtures, Grimes says, noting that a colleagues of his recently began to look systematically at the chronic effects of this combination on several representative species of fish and shellfish. "There soon may be serious federal money available for more studies," he notes.
Despite interest in inoculating microorganisms, including those specially selected or genetically engineered to degrade crude oil, there is little to suggest that they could outperform indigenous microbes, Grimes says. Adds Atlas, "I gave up looking for such miracle ‘bugs' years ago."