Posted on 01/25/2012 7:49:44 PM PST by neverdem
It may be slimy, slippery and rather unpleasant, but seaweed actually has a surprisingly wide range of uses, being a common source of food, chemicals, medicines and cosmetics. It may soon also be a source of biofuel, thanks to an engineered microbe able to transform seaweed directly into ethanol.
Seaweed has a number of important advantages over other biofuel feedstocks. Unlike maize and sugarcane, it isn't grown on fields that otherwise would be producing food and unlike wood and energy crops, such as switchgrass, it doesn't contain any lignin, which makes the sugar molecules in it much easier to release.
As a consequence, seaweed is garnering an increasing amount of interest as a potential biofuel feedstock, especially in countries with extensive coastlines. Last year, Norway opened its new Centre for Seaweed and Kelp Technology, which will focus on developing ways to generate energy from seaweed.
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Farming seaweed could be a cheap way to produce biofuel
© Bio Architecture Lab
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Unfortunately, although it's easy to release sugar molecules from seaweed, it's not at all easy for microbes such as yeast to ferment those sugar molecules into ethanol. Brown macroalgae, a seaweed found all over the world, especially in colder seas, mainly contains the sugars glucan, mannitol and alginate. Yeast can ferment glucan pretty well, but struggles with mannitol and has no luck at all with alginate.
So, scientists at the US advanced biofuel company Bio Architecture Lab set about genetically engineering a microbe that could ferment alginate, which meant endowing it with a daunting list of abilities. As well as being able to produce a class of enzymes known as alginate lysases, which break down alginate into smaller sugar molecules, the engineered microbe also needed to secrete those enzymes into the external environment, where they can interact with the seaweed. It then needs to be able to transport the sugar molecules into its body and ferment them into ethanol.
Fortunately, the scientists found many of the genes needed to perform these feats in a single marine bacteria called Vibrio splendidus, although transferring them over into the laboratory workhorse Escherichia coli proved no easy matter. 'It required multi-gene components comprising over 20 genes,' Yasuo Yoshikuni, lead scientist and founder of Bio Architecture Lab tells Chemistry World. To complete the organism they added a fermentation pathway and deleted some E coli genes that might interfere with the whole process.
Testing this engineered E coli strain on a species of brown algae, Saccharina japonica, the scientists found that it was indeed able to ferment alginate into ethanol. Furthermore, this bacterium also proved better at fermenting mannitol than conventional yeast. As a result, it was able to synthesise ethanol from seaweed at a rate of 0.64g/litre/hour, representing over 80% of the maximum possible yield.
Yoshikuni and his colleagues are now using this engineered E coli as the basis of a commercial production process. The company is currently constructing a pilot plant in Chile, where they already operate four seaweed farms, and expects it to become operational in July.
Science, 2012, 335, 308-313 (DOI: 10.1126/science.1214547)
I wonder if using dead people for fuel is ok.
Just thinking ahead.
No, that would interrupt the supply of Soylent Green.
In this case the land, water, and sunshine are vast and free for the taking. This opens up 70% of Earth's surface/70% of the Earth's available solar energy which we are not currently using for much. Sun blocking cloud cover is greatly reduced over the open oceans away from land. Even if growing efficiency is very low, all we need is a low cost harvesting technology to make this work. For thousands of years we used whales to do this harvesting but we're going to need something more scalable. We could replace the entire petroleum industry using less than 2 percent of the ocean surface, and it's carbon neutral on a large scale.
OTOH it seems according to the WSJ today that liquid rather than gaseous fuel is dramatically more valuable because of its superior portability for transportation/mobile power.
Thanks neverdem.
Thanks neverdem.
Here's something about that from 2008. Wonder how their study has come along?
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Milfoil to be studied as biofuel
October 2008
U.S. Water News Online
SPOKANE, Wash. — Ask boaters, dock owners, swimmers or scientists and you're likely to get the same answer — Eurasian milfoil is a good-for-nothing pest.
Since the mid-1970s, the feathery water plant has spread in the Inland Northwest's rivers and lakes, and hundreds of thousands of dollars are spent battling it each year.
Now a couple from Elk, Wash., has come up with a new idea — what if harvested milfoil could be turned into biofuel?
“I got the idea while I was reading a document about biodiversity,” said Alanna Mitchell, a supervisor with the Pend Oreille Conservation District. “I made a note in the margin, asking how can you come at problems like milfoil and handle them more comprehensively?”
Currently, milfoil is pulled out of lakes and streams using various equipment and simple manpower, or killed off by applying herbicides.
The plant is so nutrient-rich it burns other vegetation when piled on the shoreline.
“It was the harvesting that was the clue,” Mitchell said. “I mean, we already have this stuff. I was wondering if we could use it for something.”
Another consideration was the debate over using corn as a fuel source.
“One wants to go green, but one doesn't want to deplete a food source,” Mitchell said.
Mitchell and her husband, Cesar “Sandy” Clavell, who both have backgrounds in environmental sciences, applied for a grant through the Washington state Department of Ecology. The couple received about $8,000 for initial research.
They plan to investigate two methods of extracting oil from the water plants for use in biofuels — distilling and using solvents. What's left of the plant after each process will be composted and tested.
Students at Selkirk High School will be doing most of the research.
“Sandy is just a neat guy that he would think of including us in the first place,” said John Kinney, science and math teacher at Selkirk High School. The school has a certified water quality research lab, which came about because the rural school runs its own wastewater treatment plant and water system.
“We do water testing for many of the small towns around here,” Kinney said, adding that his environmental science class, and possibly some of the chemistry students, will be working on Mitchell and Clavell's research project.
“It's great for the students because this is for real, and it's an example of classic research,” said Kinney. “The kids get to see how it's done, how you explore all the variables and experience how the excitement sometimes wears off. Research can get tedious because you do the same thing over and over again.”
Ron Curren, public works director for Pend Oreille County, said it would be ideal if milfoil could be used for something.
Curren is waiting for a $200,000 milfoil harvester to arrive within the next couple of weeks..........
www.uswaternews.com/archives/arcquality/8milftoxx10.html
The environazis are causing all sorts of ignorant opposition to fracking.
OTOH it seems according to the WSJ today that liquid rather than gaseous fuel is dramatically more valuable because of its superior portability for transportation/mobile power.
Ethanol has more energy density as a liquid, and it's a chemical commodity. It can be used as a solvent or reagent for making other molecules, e.g. ethanol will react with organic acids to make esters as in polyester.
Cheap energy, the opposite of Obama's stated desire, will help getting out of the Great Recession.
What the heck is wrong with the renewable energy industry? Do they hate the environment that much? Coastal water areas are already heavily damaged ecological zones thanks to human activity on land, not to mention over fishing. And now they want to start harvesting the plants? Do they really want to destroy all fish stock that much?
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