When oil companies build large offshore drilling rigs, they may actually be pushing a viable source of renewable energy to the side. The results of a peer-reviewed study published in the January 20 issue of Science suggest that seaweed, of all things, is an ideal source of biofuel.
Researchers from Bio Architecture Lab, Inc. (BAL) and the University of Washington found that by successfully breaking down the complex sugars found in brown seaweed, they could produce ethanol.
Seaweed lacks a polymer called lignin, the compound that makes plants stiff, and therefore more difficult to extract biofuel from. While this alone makes seaweed, or macro-algae, a more appealing source of biofuel than corn or sugar cane, the complex sugar compound it does have, alginate, has been impossible to break down until now.
To complete this process, the researchers needed to find a microbe that could metabolize alginate to produce ethanol. Since there are no industrial microbes that can do that, the team modified the DNA of Escherichia coli bacterium, or E. coli. By introducing both the genetically tailored microbe and an "enthanol-producing" pathway to the seaweed, ethanol was created.
So, if drawing biofuel from macro-algae is so complex, what makes it a better option than corn? It turns out that experts say it's remarkably cleaner and more efficient to produce. Seaweed is harvested in a field that takes up two-thirds of the planet – the ocean – which means there would be no need to clear fertile land for cultivation, and the crop doesn't take up space that could otherwise be used for food production. Additionally, harvesting seaweed doesn't require freshwater or fertilizer.
Dan Trunfio, BAL's chief executive, told The New York Times that at a fraction of the cost, seaweed produces 50 percent more ethanol per acre than sugar cane and triple that of corn. He added that BAL could be selling renewable chemicals by 2014 and fuel made by this process by 2017.