As a youngster, I watched my mom make wine from beet juice. She put yeast on a piece of toast and floated it in a crock full of beet juice. A few weeks later I discovered the effects of intoxification when I sneaked too many sips.
Alcoholic drinks like beer or wine and biofuels like ethanol or iso-butanol are manufactured by adding yeast to a liquid mixture containing sugar. Yeast will die, though, when the alcohol content is too high. If yeast could be modified to withstand a higher alcohol content, the alcohol yield from fermentation would be higher. This would make biofuel production more economical.
A University of Illinois reseach paper in August 20 issue of the Journal of Biotechnology describes how an overexpression of certain genes effected alcohol yields. "One strain in which INO1 was overexpressed elicited an increase of more than 70 percent for ethanol volume and more than 340 percent for ethanol tolerance when compared to the control strain".
Yong-Su Jin and colleages from the University of Illinois metabolic engineer, worked with Saccharomyces cerevisiae, the microbe most often used in making ethanol, to identify four genes (MSN2, DOG1, HAL1, and INO1) that improve tolerance to ethanol and iso-butanol when they are overexpressed.
Further study of these genes should increase alcohol tolerance even further, and that will translate into cost savings and greater efficiency during biofuel production. U of Illinois press release
Courtesy Robert I. McDonaldRenewable energy is awesome! Do not read me wrong. However, there are many things to take into account when we think about a new energy technology like wind or ethanol. Like, how much land do we need to devote to producing that energy? A new study shows that some darlings of the renewable fuels set are pretty land intensive (NPR story on energy sprawl). What's the least land intensive? Reducing our consumption....gulp.
(With the Republican National Convention literally across the street, the Science Museum of Minnesota will be closed starting Friday, August 29. But Science Buzz marches on! To honor our convention guests, I’ll be posting entries focusing on issues where science and politics overlap. Hopefully this will spur some discussion. Or at least tick some people off. Previous entries here, here, here, here and here.)
In 2005, Congress passed a law requiring that set levels of renewable fuels, such as ethanol, be blended into gasoline, with the amount rising every year. Ethanol is usually made from corn, and increasing the demand for ethanol has pushed up the price of food.
In August, the state of Texas asked the Environmental Protection Agency for a waiver from the requirements, claiming that higher corn prices were making cattle farming unprofitable. And, ironically, making ethanol production unprofitable, too. The EPA reused.
Some bloggers argue that this refusal puts upward pressure on food prices—a fact that is beginning to hurt poor people the world over. Robert Zoellick, president of the World Bank, has argued for a “safety-valve” that would let refiners miss their targets if food prices rise too high.
Subsidies and tariffs also keep the price of ethanol artificially high. If these wee dropped, the incentives to turn corn into fuel would lessen, and food prices would stabilize.
Pistons roar to life.
Rice wine burns in the engine.
Go on, drink and drive.
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Sci-ku ™ -- haiku in the service of science!
We’ve talked a couple of times before about using corn to produce ethanol, and how this increases the demand for corn and thus the price. Well, now there’s more bad news: the recent flooding in the Midwest is wiping out some farmers’ fields, reducing this year’s corn crop and pushing prices to an all-time high.
Well, probably neither. But ethanol – a type of fuel made from plants – has been causing a lot of controversy lately. We’ve talked about this here before.
Many people like ethanol. As the price of gasoline rises, ethanol becomes an economical alternative. We can grow it at home, and not have to buy it from foreign countries who may or may not be our friends. And using it as fuel does not add any extra carbon into the atmosphere.
The problem is, most ethanol today is made from food crops, like corn. The more food we turn into ethanol, the less there is to eat. This puts pressure on food prices, as do droughts and growing populations. Food riots have broken out in several countries, and some people are beginning to rethink the push toward ethanol.
However, not everybody sees this as gloom-and-doom. Here's a spirited defense of biofuels.
Dennis Avery, Director of the Center for Global Food Issues, argues that the push for ethanol is hurting the movement toward sustainable farming.
However, blogger Austin Bay argues that, while rising demand for ethanol is a factor in food prices, it is far from the only one, or even the most important.
A scientific convention right here in Minneapolis agrees, noting that the problem isn’t biofuel per se, but the use of food crops to make biofuel. If we used non-food crops, we would relieve some pressure on food prices. Furthermore, non-food crops like native prairie grass actually make better ethanol than corn does!
Ronald Bailey, science correspondent for Reason magazine, notes the effect of ethanol on food prices, and makes some suggestions for reversing the trend.
Scientists in Tennessee are working on just that, using switchgrass to make ethanol. Meanwhile, researchers at the University of Massachusetts are making progress towards turning switchgrass straight into “green gasoline” – a substance chemically identical to gasoline (unlike ethanol, which has some important differences.)
(We’ve discussed switchgrass on Science Buzz before.)
Researchers in Texas are working to make ethanol from sweet sorghum. This would reduce the need to use corn, but sorghum is used in syrup and other sweeteners, so it really wouldn’t solve the food-into-fuel problem.
Right now, ethanol is expensive to make; the only reason it is priced competitively with gasoline is because the government subsidizes it with tax dollars. General Motors is partnering with Coskata, a biofuel company, to create low-cost ethanol. The new process uses micro-organisms to turn just about any carbon-based material into ethanol, including switchgrass and agricultural waste. Not only will this make ethanol cheaper, but it will also reduce the use of grains to make ethanol when they could be used to make food.
Most ethanol is currently made from corn. Scientists in Europe are worried that increasing production for ethanol will increase the demand for the crop, thus leading cut down forests to plant more corn. This would have a greater negative impact on the global climate than any positive impact from using ethanol instead of gasoline.
Meanwhile, researchers at the University of Minnesota and some place called "Princeton" have learned that converting forests and prairies into farmlands to grow corn actually releases carbon into the atmosphere, far more than is saved by replacing gas with ethanol.
OTOH, this author claims there is no evidence that forests and prairies are being converted to farm land. Rather, the demand for corn is being met by more efficient farming. He also argues that ethanol is cost-efficient and does not lead to higher food prices.
Courtesy U S Govt
Kenneth Vogel, a geneticist with the U.S. Department of Agriculture in Lincoln, Nebraska, and his colleagues, found that ethanol produced from switchgrass yields 540% of the energy used to grow, harvest, and process it into ethanol.
Their results, published online in Proceedings of the National Academy of Sciences, shows that switchgrass, farmed using conventional agricultural practices on less-than-prime cropland yields only slightly less ethanol per hectare on average than corn.
Farmers planted switchgrass on 10 farms, each of which was between 3 and 9 hectares. They then tracked the inputs they used--diesel for farm equipment and transporting the harvested grasses, for example--as well as the amount of grass they raised over a 5-year period. ScienceNOW Daily News
Anyone remember our Buzz post "Chalk one up for diversity"? David Tilman in that post is quoted saying, "diverse prairie grasslands are 240 percent more productive than grasslands with a single prairie species"
Now I read:
... Vogel says, is that yields on farms using fertilizer and other inputs, such as herbicides and diesel fuel for farm machinery, were as much as six times higher than yields on farms that used little or no fertilizer, herbicides, or other inputs to grow a mixture of native prairie grasses. ScienceNOW Daily News
Who is right? Can anyone explain why two reputable researchers are getting such different results?