Scientists have engineered a bacterium that breaks down seaweed, such as this Macrocystis species, to yield fuels such as ethanol.

[웃 910]

Seaweed study fuels bioenergy enthusiasm

Engineered E. coli can convert cell wall component into ethanol Seaweed has long made biofuel prospectors drool, but they hadn't figured out how to efficiently chew through the stuff — until now. Researchers have engineered a bacterium that can break down and digest seaweed's gummy cell walls to yield ethanol and other useful compounds. If scientists can make the process work at larger scales, seaweed could soon be a serious contender as a source of renewable fuel.

The new research "makes a pretty large leap forward," says metabolic engineer Hal Alper of the University of Texas at Austin. Unlike corn and many other biofuel feedstocks, seaweed doesn't need arable land, fertilizer or freshwater. If seaweed can be efficiently munched into ethanol, it broadens the biofuel horizon, says Alper, who was not involved in the research. Seaweed, he says, may be "that new source for unconventional carbon that everyone's been looking for."

Scientists from Bio Architecture Lab, a biofuel and renewable chemicals company headquartered in Berkeley, Calif., were interested in creating a biofuel bacterium that is a one-stop shop: They wanted a microbe that could efficiently digest the seaweed cellular building block alginate without pretreatment with chemicals or heat. Alginate is commonly used in ice creams and some textiles, but has proved difficult to break down and metabolize into fuel.

So, led by synthetic biologist Yasuo Yoshikuni, the team took the workhorse bacterium E. coli and within it, patched together the genes and other parts needed for superior seaweed-to-fuel conversion. From the marine bacteriumPseudoalteromonas, the scientists used genes for an enzyme that cuts alginate into smaller molecular bits. The researchers rigged these genes to a cellular transport system already found in E. coli, so the bacterium would secrete the alginate-slicing enzyme into its environment.

Then the team scoured scientific literature and databases for a microbe with serious alginate-digesting machinery. They hit upon the marine microbe Vibrio splendidus, and took a hefty chunk of the Vibrio DNA for use in the E. coli. When the team fed alginate to their engineered E. coli, the microbes pumped out ethanol, the researchers report in the Jan. 20 Science. The system yields 80 percent of the theoretical maximum amount of ethanol for a given amount of biomass, the scientists noted, and with further tweaking will probably be even more efficient.

Part of the beauty of the system is its flexibility, says Yoshikuni. Because the alginate-degrading enzyme is released into the environment, initial breakdown products can easily be harvested for creating useful compounds such as precursors to nylon or plastics. And when E. coli consume the broken-down alginate the bacteria generate a lot of pyruvate, a chemical intermediate useful for making fuels such as butanol or biodiesel.

Seaweed is already harvested at commercial scale in several countries for other uses, and Bio Architecture Lab is working on a pilot plant in Chile to convert seaweed into fuel, says company CEO Daniel Trunfio. Also, any seaweed will do, he notes. "We like to say we're seaweed agnostic — we can process any brown algae."

http://www.sciencene...ergy_enthusiasm

Edited January 21, 2012 by ☠

[Mr. Big Dog 10,747]

**. Prepare for rising prices at your local sushi place and forget about the seaweed salad. May as well order truffel and caviar.

[Obama 2012 1,714]

figured out how to stop ethanol from destroying engines?

[Mr. Big Dog 10,747]

figured out how to stop ethanol from destroying engines?

My last car had close to 200K miles and there was nothing wrong with the engine. Ever. It ran it's entire lifetime on the 90/10 mix. What destruction should have occurred to the engine because of the ethanol? Whatever that damage would be, nobody seemed to have told my old car about it. Or it just didn't listen.