Researchers at the Bio Architecture Lab and the University of Washington in Seattle have genetically modified a microbe commonly found in the human stomach to enable it to break down the very exotic sugars found in seaweed. The development could signify a biofuel breakthrough, since seaweed doesn’t take up space that crops could use, it doesn’t contain the hard to break down substance lignin, and it needs absolutely no fertilizers to grow. The newly found process also doesn’t require high temperatures, which means that turning seaweed into biofuel would require very little electricity.
“About 60 percent of the dry biomass of seaweed are sugars, and more than half of those are locked in a single sugar – alginate,” said Daniel Trunfio, Chief Executive Officer at Bio Architecture Lab. “Our scientists have developed a pathway to metabolize the alginate, allowing us to unlock all the sugars in seaweed, which therefore makes macroalgae an economical alternative feedstock for the production of renewable fuels and chemicals.”
When the researchers looked into turning seaweed into biofuel they realized there were no industrial microbes that were capable of breaking down alginate, so they created their own. They took a strain of E. coli bacteria — most common as a contaminant in food but which also occurs naturally in the human stomach — and genetically modified it so that it could efficiently break seaweed down and release the alginate. The researchers are using a kind of edible kelp called kombu in their study which can be grown for harvest in the ocean without any additives or fertilizers. An added bonus of using seaweed instead of other plants is that most plants contain lignin, the stiffening agent in stalks which is very difficult to break down.
The debate of biofuels is heated with opponents warning that growing crops for fuel will force food prices higher and therefore cause mass hunger around the world, especially in places where food shortages are already an issue. The prospect of seaweed as fuel is a positive one as it doesn’t impede on land currently used to grow edible crops. “BAL’s technology to ferment a seaweed feedstock to renewable fuels and chemicals has created an entirely new pathway for biofuels development, one that is no longer constrained to terrestrial sources,” says ARPA-E Program Director Dr. Jonathan Burbaum. “When fully developed and deployed, large scale seaweed cultivation combined with BAL’s technology promises to produce renewable fuels and chemicals without forcing a tradeoff with conventional food crops such as corn or sugarcane.”