Listen Now Download as mp3 from the show Vitamin D: Shedding light on diabetes, MS and cancer
Already a major contributor to the food and fertiliser industries, seaweed could also hold the key to low cost biofuels thanks to the creation of an algae-eating strain of E. coli.
Writing in Science, Adam Wargacki and his colleagues from the US-based company BAL, which stands for Bio Architecture Lab, have developed a modified form of the E. coli bacterium capable of unlocking the chemical energy stored inside seaweeds and turning it into ethanol.
In tests, their re-engineered bugs work with an efficiency of over 80% and are able to generate alcohol concentrations on par with processes currently used to produce bioethanol from arable crop waste.
The major hurdle the team needed to overcome is the fact that, in seaweed, a large amount of the energy is stored in the form of a complex sugar called alginate, which is difficult for individual bacterial strains to break down, let alone ferment to alcohol.
To engineer a seafood-favouring form of E. coli, the BAL team "borrowed" genes from other organisms and used them to "tool up" their new bug strain. These included adding a secretable Pseudoalteromonas "alginate lyase", which breaks up the seaweed alginates into smaller, more-digestible fragments, and a family of genes, from a water-borne bug called Vibrio splendidus, that transport these alginates into the bacteria and then break them down.
Set to work on a diet of the common brown seaweed Saccharina japonica, the engineered E. coli yielded alcohol concentrations of 4.7% within 48 hours. Exploiting seaweed in this way offers major advantages over traditional approaches to biofuel production.
Feasibility studies have suggested that each hectare of sea would yield a dry-weight of 59 tonnes per year, which could produce as much as 19,000 litres of bioethanol, which is twice what cane can do and five times the yield achieved from maize.
And as the team point out, seaweed aquaculture would not require arable land and therefore would not impact on food production, it doesn't require fertilisers and may even help to decontaminate nitrogen-polluted water and, even more critically, this form of farming does not require irrigation!
"which is twice what cane can do and five times the yield achieved from maize"
One has to consider that there are already critters in the ocean, many of which eat seaweed. And, at least those critters living on the continental shelves are in fact part of our food chain.
Short and to the point. Not if Big Oil has anything to say about it. And they always do! Gordian Knot, Mon, 23rd Jan 2012
Now, now! No reason to get silly on me Geezer. :) Big Oil has bought many friends in Washington. Their lobby is very powerful. Do you believe that if some bloke came up with a cheap, clean, abundant energy source that Big Oil would just shrug their collective shoulders and say "Oh well it was great while it lasted?"
Sure - all business operates on the basis of making money. They have an obligation to their shareholders to do that. My objection is to the expression "big oil", which implies that there is a cartel controlling everything from some a smoke filled room (probably leased from the Knights Templar).
In fact, I believe that "big oil" is one of the big investors in alternative energy.
Geezer, Clifford, let me ask you this.
Of course, there have been changes.
OK - I suppose GK is entitled to his opinion. Can we please try to return to the original topic? Geezer, Tue, 24th Jan 2012
Here's more by the Wall Street Journal on the company mentioned. It's called Range Fuels. Different process from the seaweed idea of course.
Though this may give some relief to land based bio fuel developments, I have serious reservations concerning any meddling with the oceans.
Following up Don's point - would we in England have to be very careful? we rely on ocean and weather streams for our climate (the UK is about level with Hudson Bay, Gulf of Alaska, Sea of Okhotst - all coldish places) and could a deforestation of part of the ocean floor have a knock on effect on the ocean currents. imatfaal, Tue, 24th Jan 2012
The oceans cover about 71% of the Earth, although the continental shelves would be a much smaller percentage.