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Seaweed may well be an ideal plant to turn into biofuel. It grows in much of the two thirds of the planet that is underwater, so it wouldn't crowd out food crops the way corn for ethanol does. Because it draws its own nutrients and water from the sea, it requires no fertilizer or irrigation. Most importantly for would-be biofuel-makers, it contains no lignin—a strong strand of complex sugars that stiffens plant stalks and poses a big obstacle to turning land-based plants such as switchgrass into biofuel.

Researchers at Bio Architecture Lab, Inc., (BAL) and the University of Washington in Seattle have now taken the first step to exploit the natural advantages of seaweed. They have built a microbe capable of digesting it and converting it into ethanol or other fuels or chemicals. Synthetic biologist Yasuo Yoshikuni, a co-founder of BAL, and his colleagues took Escherichia coli, a gut bacterium most famous as a food contaminant, and made some genetic modifications that give it the ability to turn the sugars in an edible kelp called kombu into fuel. They report their findings in the January 20 issue of the journal Science.

To get his E. coli to digest kombu, Yoshikuni turned to nature—specifically, he looked into the genetics of natural microbes that can break down alginate, the predominant sugar molecule in the brown seaweed. "The form of the sugar inside the seaweed is very exotic," Yoshikuni told Scientific American. "There is no industrial microbe to break down alginate and convert it into fuels and chemical compounds."

Read more: http://www.scientificamerican.com/ar...d-into-ethanol