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Two ongoing research projects are using E. coli to create two very different types of fuel. In one project, researchers have "tweaked" E. coli so that it will produce large amounts of hydrogen. In another, E. coli is being used to create higher-chain alcohols, which can be used as a gasoline substitute.
At Texas A&M, chemical engineering professor Thomas Wood has altered a strain of E.coli so that it produces substantial amounts of hydrogen. Specifically, Wood's strain produces 140 times more hydrogen than is created in a naturally occurring process.
By selectively deleting six specific genes in E. coli's DNA, Wood has basically transformed the bacterium into a mini hydrogen-producing factory that's powered by sugar. Scientifically speaking, Wood has enhanced the bacteria's naturally occurring glucose-conversion process on a massive scale.
With sugar as its main power source, this strain of E. coli can now take advantage of existing and ever-expanding scientific processes aimed at producing sugar from certain crops, such as corn, Wood said.
"A lot of people are working on converting something that you grow into some kind of sugar," Wood explained. "We want to take that sugar and make it into hydrogen. We're going to get sugar from some crop somewhere. We're going to get some form of sugar-like molecule and use the bacteria to convert that into hydrogen."
Biological methods such as this are likely to reduce energy costs since these processes don't require extensive heating or electricity," Wood said.
"One of the most difficult things about chemical engineering is how you get the product," Wood explained. "In this case, it's very easy because the hydrogen is a gas, and it just bubbles out of the solution. You just catch the gas as it comes out of the glass. That's it. You have pure hydrogen."
There also are other benefits.
As might be expected, the cost of building an entirely new pipeline to transport hydrogen is a significant deterrent in the utilization of hydrogen-based fuel cell technology. In addition, there is also increased risk when transporting hydrogen.
The solution, Wood believes, is converting hydrogen on site.
"The main thing we think is you can transport things like sugar, and if you spill the sugar there is not a huge catastrophe," Wood said. "The idea is to make the hydrogen where you need it."
In related E. coli news, researchers at the UCLA Henry Samueli School of Engineering and Applied Science have developed a new method for producing next-generation biofuels by genetically modifying E.coli bacteria to be an efficient biofuel synthesizer.
Higher-chain alcohols have energy densities close to gasoline, are not as volatile or corrosive as ethanol, and do not readily absorb water. Furthermore, branched-chain alcohols, such as isobutanol, have higher-octane numbers, resulting in less knocking in engines. Isobutanol or C5 alcohols have never been produced from a renewable source with yields high enough to make them viable as a gasoline substitute.
"These alcohols are typically trace byproducts in fermentation," Liao said. "To modify an organism to produce these compounds usually results in toxicity in the cell. We bypassed this difficulty by leveraging the native metabolic networks in E. coli but altered its intracellular chemistry using genetic engineering to produce these alcohols."
The research team modified key pathways in E. coli to produce several higher-chain alcohols from glucose, including isobutanol, 1-butanol, 2-methyl-1-butanol, 3-methyl-1-butanol and 2-phenylethanol.
This strategy leverages the E. coli host's highly active amino acid biosynthetic pathway by shifting part of it to alcohol production. In particular, the research team achieved high-yield, high-specificity production of isobutanol from glucose.
This new strategy opens an unexplored frontier for biofuels production, both in coli and in other microorganisms.
"The ability to make these branched-chain higher alcohols so efficiently is surprising," Liao said. "Unlike ethanol, organisms are not used to producing these unusual alcohols, and there is no advantage for them to do so. The fact that they can be made by E. coli is even more surprising, since E. coli is not a promising host to tolerate alcohols. These results mean that these unusual alcohols in fact can be manufactured as efficiently as what evolved in nature for ethanol. Therefore, we now can explore these unusual alcohols as biofuels and are not bound by what nature has given us."
UCLA has licensed the technology through an exclusive royalty-bearing license to Gevo Inc., a Pasadena, Calif.-based company founded in 2005 and dedicated to producing biofuels.
Jim Berry: Your statements are all correct. Presently lead acid batteries would be more practical than Hydrogen, but the problems associated with Hydrogen will most likely be solved before lead acid batteries catch on. Hydrogen fuel cells have much higher energy production per weight than lead acid batteries, which means that batteries would only be a temporary solution until all the bugs get worked out of the hydrogen powered car. But, as you said, neither one of these will become popular until oil begins to run out, which will be by about 2038 according to the more reliable statistics I've seen. But I know you can only believe half of what you read.
Hydrogen as a fuel source will not replace oil, gas or coal until the those are nearly depleted.
Hydrogen is difficult to store nor does it have the raw power of petro-chemicals. For example those Hydrogen cars that make the new often have a range of only 100 miles or so. If the car sits for a week, most of the hydrogen is gone. That does not satisfy most driving needs. A lead base battery car looks more pratical than Hydrogen.
Except it's not really an issue of "Food crops"
It's an issue of "Crops" period.
There just isn't enough feedstock.
http://greyfalcon.net/biolimits.png
That said, the second part of the article has more weight than the first.
Given it's ability for direct synthesis of butanol.
A fuel with much more desirable performance charasteristics than ethanol.
Congratulations on the amazing work. I love the idea of hydrogen because of its 'water exhaust'. However we seem to be hitting the same barrier with regards to using food crops to supply sugar to feed the bacteria.
So until we have cellulosic capabilities, the immediate answer is still 1. Efficiency 2. renewables like wind, solar, biomass and biogas.
Bill Larzelere: My apologies..... I wasn't trying to point out that lead acid was a superior battery by any means. I do know that Lithium batteries are lighter and more efficient than lead acid. The point I was trying to make was that batteries will be a good short term solution, until hydrogen becomes more feasible. Though Hydroegen storage and other things are still a problem, I feel it is a hurdle that will be overcome because fuel cells have so many other advantages over batteries. Namely, they are lighterweight, more efficient, and they can pull thier oxidant out of the air instead of carrying it on board as batteries do.
Hydrogen is not there yet, and batteries are currently a better option, but until you can get Lithium batteries to send a car 350 miles on one charge, don't count on them catching on in the U.S.
Matt
Sound very interesting.
Now, E-Coli...Isn't that the main ingredient in crap?
So, the E-Coli farts, and we suck up the farts and burn them. Is that right?
My gut feeling is, this is a great idea! Anybody hungry?
There are many starving people in the world today. We need to use crop land to grow food not fuel. Brazil is an example where the Amozon is being wasted to grow fuel. There are many alternative energy possibilities to be researched Sun, wind, tides etc. that can generate electricity, which can be stored for portable (transportation) or stationary use.
Robert Stout
Southwest Solar Design
solarrs@gmail.com
congratulations for your great and advanced work!The biofuels field is a very promising scientific and applied field and all we who heve been occupied with it have to try to improve it and find out new technologies.Personally i graduated from the Agricultural University of Athens and my specialty is the applied enzymology which is a part of the biofuels production.At this time i am looking for a university in U.S.A. to make my doctorate on biofuels.Anyone who could provide me any information about this issue,please let's get in touch with me by e-mail.
i would be grateful.Thank you very much
I cannot for-see any energy source which will beat Hydrogen: That being the case why do Western Governments not pool their resources to get on top of the Hydrogen problem as they did with the development of the Atom Bomb in WW2:
Hydrogen is a wonderful clean energy source once it is used safely and therein lies the crux of the matter: However, with today's technology and the will to forge ahead we could all face a bright peaceful future away from the middle eastern oil cartels who can stick their oil where the sun don't shine:
We seem to be moving ahead with hesitant unsure steps without any direction from our leading politicians who seem to lack the courage to grab this wonderful opportunity to put us back in the lead and show the world what can be done with courage and forsight:
Hydrogen may not be the answer for transport due to the huge energy costs of compressing or liquifying it. The new technology of adsorbing it on to certain sintered light metals may or may not get around this problem. Hydrogen will come into its own as a way of storing excess energy when renewables are producing energy in excess of demand. See
http://mtkass.blogspot.com/2007/10/excess-energy-what-to-do.html
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