They don't need oxygen, they don't need sunlight. They can survive acid baths and doses of radiation 5,000 times more intense than the amount needed to kill a human. They can breathe metal, eat nuclear waste, drink boiling toxins and even heal their own wounds. Now scientists think these superbugs--known as extremophiles--may be the secret to a new energy economy.
"Climate change and the problems with carbon-based fuels has really brought this area into focus," said Bruce Rittman, the director of the Center for Environmental Biotechnology and a member of the National Academies of Engineering. "We've been working with micro-organisms for years but on a much smaller scale. Now all of a sudden it needs to be done on a massive scale throughout the world."
In the past three years, the U.S. government has invested millions of dollars to figure out how extremophiles create, collect, store and expend energy in ways once reserved to the realm of comic book superheroes. These tiny biological machines are so brutally efficient that they can convert nearly anything--nitrogen, uranium, hydrogen and methane--into life-sustaining energy, flourishing where no other forms of life can.
For example, a microscopic bug discovered two miles underground in a South African gold mine in 2006 survives exclusively on a diet of sulfur and hydrogen rather than nutrients derived from photosynthetic plants or bacteria. Other bugs flourish in boiling heat while others spend their lives buried in arctic glaciers and volcanoes. The list goes on.
"For micro-organisms, breaking down whatever energy is available is the name of the game," said Bob Kelly, a professor of microbiology at North Carolina State University and director of the Department of Energy Bioenergy Research Institute. "Whatever nature throws at these organisms, they always find a way to break it down. All of these things are energy sources and the more lean their environment, the more inclined they'll be to break down whatever energy source is available."
While a few of these bugs have attracted attention for their ability to break down biomass like switchgrass and wood chips into biofuels, bugs are being designed to solve the full spectrum of today's energy and environmental challenges.
For instance, Nate Lewis, a professor at California Institute of Technology, has identified bugs that replicate photosynthesis but achieve far greater energy yields. Rittman is working with micro-organisms that can convert solar energy into liquid fuels. Scientists at MIT are investigating bacteria that could lead to new fuel-cell technologies. Bugs are also being designed to clean water, eat carbon in coal plants, neutralize nuclear radiation and even enhance human mobility in outer space.
The industrial use of microbes began nearly a century ago. During World War I, a young chemist in Manchester named Chaim Weizmann resuscitated the dying English war effort when he discovered a microscopic organism that could convert corn into acetone--a vital ingredient of explosives that England desperately needed at the time.
Weizmann, a Russian immigrant who became a naturalized citizen of the U.K., donated his discovery to the government. As a sign of gratitude, England's prime minister, Lloyd George, signed the Balfour Declaration, which led to the creation of the state of Israel and the modern Middle East.
Nearly a century later, scientists have genetically engineered new strains of the same bug Weizmann discovered could convert corn into acetone to produce second-generation biofuels. Gevo, a biofuels start-up based in Pasadena, Calif., is commercializing a second-generation biofuel called butanol developed from Weizmann's bug.
Gevo is among a small group of companies backed by biofuels evangelist Vinod Khosla that have benefited from a sprawling government energy research project that began nearly a decade ago. In 2001, the U.S. Department of Energy launched the Genomics: GTL, which explicitly sought to marshal the resources made available by the Human Genome Project to "develop new sources of energy, mitigate the long-term impacts of climate change, clean up the environment, reduce the threat of biological terrorism, and protect people from adverse effects of exposure to environmental toxins and radiation."
Since 2005, a rash of energy-related legislation like the America COMPETES Act and the Advanced Energy Initiative has accelerated the pace and scale of research in the program. New agencies like ARPA-E, agency within the Energy Department modeled on DARPA, and nearly a dozen regional bioenergy research centers have added institutional support and intellectual firepower.
The program, which has spilled over into the departments of Agriculture, Commerce and Defense, has brought the nascent fields of metagenomics and synthetic biology to design bugs and communities of bugs to scrub carbon from coal, convert sunlight into liquid fuels, clean dirty water, store energy and unlock the secrets of surviving space travel.
Although biofuels products have already begun to migrate from GTL-funded research to commercial markets, the full impact Genomics:GTL is likely to have on the future of energy and climate change is nowhere near completion. Contrary to what many people think, the new frontiers of clean energy are still frontiers and the search for better bugs has only just begun.
"People talk about this stuff like it's so mature and developed," said Pat Gruber, the CEO of GEVO. "The truth is that this stuff is still in its freaking infancy."