By Janet Raloff
When the Deepwater Horizon accident spewed millions of barrels of oil into the Gulf of Mexico last year, surface bacteria launched into a feeding frenzy, a new study finds. But microbes that gobbled up the surface oil did so without increasing their numbers or gaining weight.
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Waters in much of the Gulf are fairly mineral poor, at least in terms of what microbes need to flourish, says chemical oceanographer Benjamin Van Mooy of the Woods Hole Oceanographic Institution in Massachusetts. He and his team expected that microbes encountering the surface oil slick would turn up their figurative noses at the petroleum smorgasbord. To the scientists’ surprise, local bacteria pigged out, more than quintupling their normal daily intake with no increase in their mass. The researchers describe their findings online August 3 in Environmental Research Letters.
“You can imagine these bugs are like Richard Simmons,” whose Sweatin’ to the Oldies aerobics videos advocate exercise to rev up the body’s calorie expenditures, Van Mooy says. In the Gulf, “microbes can gorge on the petroleum buffet but not gain weight because their metabolism is high.”