Researchers engineer microbe to make seaweed a cost-effective source of renewable fuel
By Darren Quick
January 19, 2012
One of the biggest criticisms leveled at biofuels that are derived from crops such as wheat, corn and sugar cane, is that they result in valuable land being taken away from food production. For this reason there are various research efforts underway to turn seaweed into a viable renewable source of biomass. Now a team from Bio Architecture Lab (BAL) claims to have developed a breakthrough technology that makes seaweed a cost-effective source of biomass by engineering a microbe that can extract all the major sugars in seaweed and convert them into renewable fuels and chemicals.
Because of its high sugar content, the fact it doesn't require arable land or freshwater to grow, and is environmentally friendly, seaweed is seen as an ideal global feedstock for the commercial production of biofuels and renewable chemicals. According to BAL, less than three percent of the coastal waters globally is all that's required to produce enough seaweed capable of replacing over 60 billion gallons (227 billion liters) of fossil fuel annually.
The BAL team's breakthrough, which could help make this underutilized resource much more economically attractive, centers around an enzyme that is able to unlock and metabolize the polysaccharides within the seaweed.
"About 60 percent of the dry biomass of seaweed are fermentable carbohydrates, and approximately half of those are locked in a single carbohydrate - alginate," said Daniel Trunfio, Chief Executive Officer at Bio Architecture Lab. "Our scientists have engineered an enzyme to degrade and a pathway to metabolize the alginate, allowing us to utilize all the major sugars in seaweed, which therefore makes the biomass an economical feedstock for the production of renewable fuels and chemicals."
BAL was a co-recipient of an award for the development of a process to convert sugars from seaweed into isobutanol from the U.S. Department of Energy's new Advanced Research Projects Agency - Energy (ARPA-E).
"BAL's technology to ferment a seaweed feedstock to renewable fuels and chemicals has suggested 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."
The BAL team's breakthrough is detailed in an article entitled "An Engineered Microbial Platform for Direct Biofuel Production from Brown Macroalgae", which appears in the January 20 issue of Science.