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Grad student Phong V.V. Le stands with Professor Praveen Kumar in front of a stand of grass. The pair found a potential downside of switchgrass as a biofuel stock -- decreased soil moisture and increased humidity.  (Source: L. Brian Stauffer/University of Illinois)

A new study created a strain of yeast more efficient at turning red algae to fuel via fermentation. The new strand requires only half the time of its predecessor to produce biofuel.  (Source: Antibiotics for)

Algae/seaweed-based biofuels may be the ideal solution for sea-bordering arid regions, such as the Middle East.  (Source: Google Images)
Water usage is a potential concern for using switchgrass as a cellulosic biofuel feedstock

You can ferment it in bacteria.  You can subject it to outlandish temperatures and pressures.  But however you produce biofuel, one thing is constant -- you need a supply of carbon, the "feedstock".

I. Switchgrass == Environmental Threat?

One leading candidate for widespread use as a biofuel feedstock is switchgrass.  Fast-growing and hardy, switchgrass quickly produces a great deal of biomass.  But a new study by the
University of Illinois reveals a potential downside -- switchgrass' growth comes at the cost of soil moisture.

Switchgrass is apparently so effective at sucking water out of the ground that it could cause adverse affects to other human crops, as well as local ecosystems.  
Praveen Kumar, the Lovell Professor of civil and environmental engineering at the University of Illinois states, "While we are looking for solutions for energy through bioenergy crops, dependence on water gets ignored, and water can be a significant limiting factor.  There are many countries around the world that are looking into biofuel energy, but if they are adopting these (large grasses) into their regular policy, then they need to take into account the considerations for the associated demand for water."

The study examined transpiration -- the loss of water through plant pores.  Ultimately
switchgrass and another fast growing grass, Miscanthus, transpire at a higher rate than corn (the most widely used ethanol biofuel crop) and thus pull water from the soil at a faster rate.  This dries the soil and increases humidity.

The researchers also used a predictive model to study what would happen if the predictions of global warming
 were realized.  What they found was that while higher carbon dioxide levels decreased the transpiration rate by allowing the plant to open its pores to the air less frequently, higher temperatures negated this affect by increasing the rate of water loss while the pores were open.  Overall, the predicted affect was even higher rates of water loss.

Regardless of whether the warming scenario occurs, however, the study raises concerns for the viability of switchgrass and Miscanthus as biofuel feedstocks, particularly in drought-prone regions.

The study was published
 [abstract] in the peer-reviewed journal PNAS (Proceedings of the National Academy of Sciences).

Of course, the pro-corn, anti-grass bent should be taken with a grain of salt.  The University of Illinois has a long-standing relationship
 with the corn ethanol community, which would be displaced in a move to switchgrass cellulosic ethanol.  While this particular study was funded by a National Science Foundation grant, given the overall financial situation, it's possible that researchers at the University of Illinois could feel incentivized to find downsides of switchgrass and the upsides of corn.

II. Algae Could be the Cream of the Crop

That said, the University of Illinois, in a separate study, is promoting a fascinating biofuel alternative
 to both corn ethanol and switchgrass -- seaweed.  Recent efforts by the U.S. Marine Corps have heated up interested in algae- and seaweed-based biofuels.

The new study looks at how to speed up the slow process of fermenting red seaweed biomass to produce biofuel.  Currently Saccharomyces cerevisiae -- commonly named yeast -- is the leading candidate for fermentation as it has genes which code for proteins capable of digesting both galactose and glucose -- the two primary sugars in red seaweed.  However, wild-variety yeast "eats" glucose before it will eat galactose, making the fermentation process slow, and thus, ultimately, more expensive.

By introducing a new sugar transporter and enzyme that breaks down cellobiose at the intracellular level via a bit of gene splicing, the team was able to create a strain of yeast that simultaneously digests galactose and glucose, cutting the production time of red seaweed-derived biofuel in half.

Yong-Su Jin, an assistant professor of microbial genomics, compared the development "to a person taking first a bite of a cheeseburger, then a bite of pickle. The process that uses the new strain puts the pickle in the cheeseburger sandwich so both foods are consumed at the same time."

Professor Jin says that the pre-treatment process to break down seaweed into cellobiose -- glucose pairs -- and galactose is considerably less toxic than many of the potential processes to break down cellulose from terrestrial crops.  Furthermore, he says that red seaweed has several other advantage as well, including its higher biomass-per-unit-area density, its higher rate of carbon fixation than terrestrial biofuels crops, and its ability to grow in the sea, thus escaping land-space constraints.

The researcher selected the red variety (Gelidium amansii) of seaweed as it’s a fast-growing variety found in abundance in one very space-constrained region -- Southeast Asia.

The study on the work was published [abstract] in the peer-reviewed journal Applied and Environmental Microbiology
.  The study follows work earlier this year published [abstract] in PNAS, which saw Professor Jin's team introduce pathways for simultaneous digesting of xylose -- another plant sugar -- and cellobiose into a yeast strain.

Together the studies paint an interesting picture.  Switchgrass is potentially undesirable in arid regions and in space-confined regions.  However, many of these same regions border the sea.

So for regions like the Southeastern United States, Southeast Asia, the Middle East, and Japan, growing biofuels in the sea might be the wisest approach of all.



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Biofuel/Food == WATER
By rdhood on 8/30/2011 12:30:39 PM , Rating: 0
Listening to NPR (yes, a liberal Mecca, but sometimes makes good points) on a piece on food sources/movement around the world, and one comes to the realization that when a country purchases grain, or land to grow grain (as China has), what they are REALLY purchasing is water. Grain requires water to grow. Countries with limited water supplies must purchase their grain elsewhere. So whether we are talking about switchgrass, corn or wheat, we are talking about using huge water resources to create food or fuel. Frankly, our aquifers are more important than biodiesel. We should not be depleting our stored-water sources... which could take hundreds or thousands of years to replenish... to produce corn or switchgrass for biodiesel or alcohol.

If we are growing this stuff where ample water falls out of the sky to maintain soil moisture... great. Otherwise, the search for biomass and the process to convert it to biodiesel continues.




RE: Biofuel/Food == WATER
By BioHazardous on 8/30/2011 12:45:23 PM , Rating: 2
quote:
If we are growing this stuff where ample water falls out of the sky to maintain soil moisture... great. Otherwise, the search for biomass and the process to convert it to biodiesel continues.


So what I'm hearing you say is you didn't read the article and went straight to commenting. The whole point of the article was using the sea/ocean (salt water) to grow seaweed.

Either that or you just like making pointless points.


RE: Biofuel/Food == WATER
By JoJoman88 on 8/30/2011 8:45:09 PM , Rating: 2
The ansewer is fuel cells. Once they get around the cost of materials needed in production of fuel cell all this biomass talk will die off. You know one day they will find a way to make fuel cells cheap and it will be game over for biomass. As many have pointed out, using food crops(corn) or the water for fuel crops(switchgrass) is foolish with the worlds population geting larger all the time. That land and water will be needed to make food.


RE: Biofuel/Food == WATER
By lagomorpha on 8/31/2011 3:53:45 AM , Rating: 2
You should probably be aware that fuel cells don't magically recharge themselves. You're going to need a power source to charge them and at the moment in North America that means coal.


RE: Biofuel/Food == WATER
By DigitalFreak on 8/30/2011 9:32:30 PM , Rating: 2
I stopped reading at the NPR is a liberal Mecca part.


RE: Biofuel/Food == WATER
By michael67 on 8/31/2011 2:51:12 AM , Rating: 2
He is right on the use of cropland for fuel, its imho almost criminal, but it really has no relevants here as we talking about seaweed as the alternative.

And guess what, ware do seaweed grow? was it not in salt water, and "I" never heard of a saltwater shortage any ware in the world.

ps. liberal and conservative Mecca are both as bad, people learn to think for your self!

Liberal talking to Conservative http://www.youtube.com/watch?v=WnzlbyTZsQY&
They both are saying a lot but no one is really listening or even understanding what the say in the other camp as they live both in different worlds.


RE: Biofuel/Food == WATER
By rdhood on 8/31/2011 9:09:00 AM , Rating: 2
quote:
So what I'm hearing you say is you didn't read the article and went straight to commenting. The whole point of the article was using the sea/ocean (salt water) to grow seaweed. Either that or you just like making pointless points.


WRONG, douchebag. This article CLEARLY made two points... One about switchgrass, and one about seaweed. YOU read the article.

I was commenting on the switchgrass... primarily because it has been hailed as the the great corn alternative to produce fuel.

I will leave others to comment about the SECOND point of this article, seaweed.


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