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Ethanol just might help America break its addiction to fossil fuels — but not if it has to be made from corn, as is typically the case today. That's why researchers and entrepreneurs are rushing to find ways to turn non-food biomass into biofuel. The key trick will be to come up with a cheaper way to produce fuel from cellulosic material, ranging from corncobs to wood waste to switchgrass.
It'd be great if brewer's yeast, the humble one-celled organism that biofuel producers use to make ethanol, could handle cellulose as well as it handles simpler sugars. That would cut down on all the enzymatic processing that's currently required to get the party started.
Well, it turns out that researchers at the University of California at Berkeley are trying to teach that old brewer's yeast new tricks, by inserting genes from a type of fungus that can digest cellulose. The fungus, Neurospora crassa, can't produce alcohol. But the researchers conducted a genome-wide analysis of the critter and found a family of genes that appeared to facilitate the transport of more complex sugars into the cell. When the right genes were spliced into brewer's yeast (Saccharomyces cerevisiae), two of the resulting strains could grow on cellodextrin as well as the usual glucose. One strain produced 60 percent more alcohol than normal yeast when grown on a type of cellodextrin known as cellobiose.
"This improvement over the wild organism is a proof-of-principle that allows us to take the technology to the next level, with the goal of engineering yeast that can digest and ferment plant material in one pot," Jamie Cate, a member of the Berkeley team, said in a news release. Enzymes would still be required to break cellulose down into cellodextrins, but further genetic engineering could conceivably streamline the process further. And Cate pointed out that a wide variety of biofuels could be produced.
"The use of these cellodextrin transporters is not limited to yeast that makes ethanol," Cate said. "They could be used in any yeast that's been engineered to make, for example, other alcohols or jet fuel substitutes."
The Berkeley researchers' report was published today on the journal Science's website and will appear in a future issue. But they're not the only ones working to improve biofuel production through genetic engineering. Heck, that's one of the big reasons why genetic pioneer J. Craig Venter and others are putting so much effort into developing synthetic cells.
Here are links to other reports about yeast re-engineering:
- Chemist blends math and synthetic biology in biofuel research
- Engineer identifies genes for making biofuel more efficiently
- New yeast can ferment more sugar, make more ethanol
- Winemaking yeast could be key to alternative fuel
Some folks are already worried about the potential risks associated with "frankenfuels." The issue is definitely something to think about. If you believe re-engineering yeast to make better biofuel is scary, what would you say to combining genetically engineered yeast with human DNA to create artificial corneas? And it's not just yeast: E. coli bacteria are being tweaked as well, to produce biodiesel.
I'd love to get your honest opinion on bioengineering — so please be frank in your comments below.
Authors of the SciencExpress study, "Cellodextrin Transport in Yeast for Improved Biofuel Production," include Cate as well as Jonathan Galazka, Chaoguang Tian, William Beeson and N. Louise Glass of the University of California at Berkeley, and Bruno Martinez of Lawrence Berkeley National Laboratory.
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a cross between blade runner and gateway?
The good old days, the bad old days.
Science has an epiphany, researches, solves, develops, and wonder of wonder,,,,a new product. We have hoped and improvement to our lives. But not all improvements were improvements, many had very unintended consequences, DDT,,,Chlorofluorocarbons, irrigation, invasive foreign species.
A yeast/fungus that can break down cellulose ? How many houses are built,, structured of wood? How is this new strain to be used, manufactured, transported, disposed of? It might be a real boon if the waste 'cake' were dumped in the local landfill, the released yeasts might make short work of all of the wood, paper and many of the plastics buried in that waste mountain. And where would the dreck from that dissolution flow?
I see that there could be tremendous consequences to this new strain. Great care should be taken. Or we are gonna wake up one morning under a Mylar tent with nary a tree in sight.
what happens if this newly engineered organism gets out into the wild? Is it going to eat living trees and plants?
I tend to side with folks worrying after unintended consequences, though in general ethanol production which does not compete with food production's need for arable land seems a reasonable goal. What we sometimes lack is the discipline to manage the side effect part of any research endeavor. And from my experience, this is similar to contract negotiations: the first 5 - 10% of the effort is expended scheduling expectations to price with the balance of the diligence consumed seeking to bound all of the "backout" or negative performance implications of the venture. Allegorically, if we burn a million man-hours creating a stable genetic alternative, a "disinterested" team should budget ten million man-hours researching consequences unaligned to the end solution. Too often in crossing the bridge from research to commercial domains, insufficient (and of necessity, independent) fault analysis is conducted. The need for insight in the latter process is easily misapprehended and shortchanged on the way to securing windfall returns...
That's a great plan. It's balanced in the right kind of lopsided way (1 million man hour create/11 million man hour reasearch) Best get started people! Before the investors hire the ad men.
While the news of cellulosicdegradation has been the subject of intense study for a very long time it remains firmly in the realm of "what if." The devil as it is said is found in the details; relatively speaking the products formed display improved yields however taken in absolute terms the results are not going to break through economic barriers. Cellulosics have two issues that need to be viewed together to understand the challenge. Chemical hydrolysis to liberate fermentable sugars (the subject of the quoted research) is only part of the problem. The more challenging issue turns out to be the physical structure of cellulosic biomass which precludes degradation in the first place.
On the subject of frankenfuels, and the bogeyman of "scientific tinkering" there is a serious misunderstanding between reality and Hollywood. Taken together with the general public's long standing poor grasp of even basic scientific principles and an overall aversion to the unknown creates an environment that wastes time and resources focused on the wrong issues. Specifically, the discussion should not be "do we or don't we?" but rather "how do we safely, and intelligently?" We all have a responsibility to make certain that everyone understand and respect the technological world in which we reside.
I think we are on the road to creating a bio-hazard for for humans - you know fungus is everywhere and animal cells use cellulose too!
Actually, most animals can't digest cellulose and therefore cannot use it.
Cockroaches are one of the few creatures that, with the assistance of a certain microorganism in their gut, can really digest cellulose. That is why they are fond of pizza boxes...
I have to agree with jhoopy56 here about the responsiblility to look for unintended consequences, which are always there, and, even when they are obvious, still manage to be unexpected. (The development of antibiotics, for example -- we always knew that bacteria were rapidly adaptable, but that didn't stop us from using the technology irresponsibly to make factory farming profitable, and that leads strait to drug-resistant superbugs. On the other hand, new technology is hardly likely to be developed if the kind of due dilligence required to prevent all future disasters is applied... My bet is that we will have some wonderful new biotechnologies in the next decade, and they will seem miraculous at first and and decade later we will discover the true costs.
Here is where common sense must be applied. There should be some way to prevent the bacteria from transporting from one nutrient source to another. We should be insisting that that be incorporated into this frankenstein bacteria.
Do these thing have a bolt through their necks or at least kept on a leash.
Cos I don't want my beer turning into ethanol
It's a step in the right direction, that direction being away from our addiction to fossil fuel. All the naysayers and end-of-the-world yellers will predict Frankie rearing his ugly larger-than-life head. None of it should be taken lightly of course. It's the only world we've got. Motorized, mechanical, electrical, nuclear, automated we are! Burning a pile of wood gathered in the receding woods nearby is too difficult! Putting things together by hand is archaic! We want it now! We want more! We want the best! We want what's next! Now what recyclables do I need to set aside?
Industry and government have a present reputation for being entirely irresponsible. Why should this be any different? No matter what is done, people are going to scream "Foul!"
After all, if we do use them, people are going to say that there is no respect for the environment and that peddling in genetics is bad... wrong. Badong, even, if you get my reference.
If we don't use them, people are going to say that there is no respect for the environment and that companies involved in fossil fuels demolished any chance these new yeasts had by using their obscene amounts of money.
It's a lose-lose situation. We can't trust industry or government to regulate themselves, at least not for the time being.
This is why I vote... in the vain hope that a large enough number of other voting Americans will agree with me that the government will change and man up to its mistakes.
Bummer.
I was hoping for a cheaper way to power my Frankenstein.
(I have to use all of the lightning bolts to keep my DeLorean charged.)
scuse me but wouldn't the multi billion dollar beer industry like to save some bucks? At 60% more yield..
do the math.