Fungus May Be the Key to Cheaper, More Efficient Biofuel


Biofuels may soon be produced quickly, efficiently, and at a cost comparable to gasoline thanks to a discovery from researchers at the Great Lakes Bioenergy Research Center. The research team has identified several genes that improve yeast’s ability to digest the natural sugar xylose. This means that it will soon be possible to efficiently produce bio-ethanol from cellulosic biomass–waste matter such as the stalks, leaves, and husks of plants, wood chips, sawdust, and dead trees–as opposed to land-intensive crops like corn. The unlikely source of the genes: fungus living symbiotically with bark beetles.

Cellulosic materials cost about half as much as corn per ton, but are historically more difficult than corn to convert to ethanol. Current strains of yeast used industrially for the purpose of converting cellulosic biomass to ethanol have difficulty fermenting the plant sugar xylose, and can do so only after all glucose is exhausted. As xylose makes up nearly half of all available plant sugars, this marks a great loss in ethanol yield.

The team chose bark beetles on account of their woody, xylose-rich habitat. By comparing the sequencing of two xylose-fermenting fungi that live alongside the beetles–Spathaspora passalidarum and Candida tenuis–the researchers was able to identify several genes that effectively increase fermentation of the sugar.

Ethanol can be used as a fuel for cars, but is usually used as a gasoline additive to increase octane and improve vehicle emissions. Production of corn-based ethanol in the United States is just over three billion gallons per year. While biodiesel offers a fossil energy ratio of 5.54 to 1, there is still apprehension about its production and use. These concerns are linked to increased food prices because of the large amount of arable land required for crops as well as the energy-intensive production process (especially corn-based fuels). With available US cropland diminishing, the ability to convert woodier waste will be an important factor in keeping bio-ethanol part of the alternative fuels discussion.

As bark beetles and their related fungi are devastating forests from the northern Rockies to the Czech Republic, it’s nice to know they may provide some great ecological benefit alongside the destruction.

Article by Allison Leahy, appearing courtesy Earth & Industry.



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2 comments on “Fungus May Be the Key to Cheaper, More Efficient Biofuel

With food prices jumping higher, in part due to corn>ethanol production, this finding of a “yeast” that can digest “biomass” that here to for has been difficult to ferment is good news. Providing “liquid fuels” at reasonable cost will be a major undertaking as we move (inexorably I trust) to a sustainable energy future.

Good article

My Critique of the above article: “Fungus May Be the Key to Cheaper, More Efficient Biofuel”

……“at a cost comparable to gasoline”

… Corn ethanol is already cheaper than gasoline and also cheaper than diesel. These are the current National avg. retail prices per gallon at the pump: reg. gasoline: $3.71…diesel: $3.97… 85% ethanol E-85: $3.27 … In fact adding ethanol to gasoline saves consumers money, by driving the price and demand of petroleum fuels downward… Furthermore, the oil-based fuels gasoline and diesel are highly subsidized. They would be even more expensive than corn ethanol if the oil subsidies were removed… The most blatant one of all is the – foreign oil investment tax credit – US taxpayers are subsidizing foreign oil… We also spend billions every year to protect foreign oil shipping lanes, pipelines, foreign oil terminals, and power plants running foreign oil infrastructure…… The cost to protect ethanol – ZERO…

If you did not blend-in cheaper ethanol, and no longer subsidized and protected foreign oil, and didn’t fight any more oil wars, then you would see the true cost of gasoline – It would be two to three times the price of corn ethanol. See: http://www.icta.org/doc/Real%20Price%20of%20Gasoline.pdf

……“as opposed to land-intensive crops like corn.”

… Why was corn residue omitted from your list – We have roughly 90 million acres a year of corn stalks, leaves, husks, and cobs. This is a huge biomass resource. Our feed corn crop is not suitable for human consumption. It does not take food out of the mouths of the hungry. It’s used to feed meat and dairy cows, hogs, poultry, and fish, which the hungry cannot afford… Twenty percent of this – Non-edible – feed corn crop is exported, mostly to China and India, reducing our trade deficit. Another 35-40 percent is used to produce ethanol. One third of that kernel of ethanol corn comes out as – distillers grains – a higher protein feed product, cheaper and superior to the corn itself. In addition to the ethanol, you also get a corn oil byproduct, about 3-5 percent more fuel feedstock for biodiesel. Add to that the 4-6 tons per acre of feed corn biomass residues, and you have the whole picture…

……“Cellulosic materials cost about half as much as corn per ton”

… Not when you consider that corn and its biomass residues will be harvested and transported together to the same biorefinery, where cellulosic ethanol production will be synergistically bolted-on to existing corn ethanol plants. This is already in the works…

Another development – Green Plains ethanol has a prototype algae farm integrated into one of its corn ethanol refineries – recycling to the algae – renewable waste CO2, waste heat and nutrient-rich thin stillage effluent. Heterotrophic algae also reproduces rapidly on sugars taken from biomass residues, so again, residues will be integrated into existing biorefineries. This corn ethanol refinery and many more like it will be re-classified as advanced biofuel. Cutting edge integration and displacement technology is revolutionizing our existing biofuel industry…

…… “Production of corn-based ethanol in the United States is just over three billion gallons per year.”

… Wrong factual information – 2010 ethanol production was over 13 BILLION gallons, and 2011 is headed over 14 billion gallons. Roughly 10% of our gasoline consumption. You’re only 11 billion gallons off…

…… “These concerns are linked to increased food prices because of the large amount of arable land required for crops as well as the energy-intensive production process (especially corn-based fuels). With available US cropland diminishing…”

…There’s no shortage of arable land in the US. We only use about a third of it. Generally, feed corn does not compete for land with other crops. The feed corn crop is no larger today than it was in 1944. Corn Acreage has NOT been expanding, because the yield per acre has steadily gone up over the years. We have a hundred years to go before we even get close to using all of our arable land for crops… No one ever squawks about urban sprawl, roads, interstate highways, pipelines, mining, and tar sands – consuming farm land and forest…

Farmers rotate corn and soybeans on their land, depending on the market price… Soy Oil is extracted from soybeans as a value added byproduct that would have otherwise been used to fatten animals eating 20% oil laden soy meal… Another advantage of extracting the oil is better feed digestibility and leaner animal products…

The best studies show that, overwhelmingly, the three biggest factors in higher food prices are: (1) The higher cost of crude oil, which makes everything more expensive to produce and ship. That impacts the cost to produce and ship corn, soy and all other commercial food products… (2) Commodities speculation has a huge impact on oil, sugar, corn, soy, wheat, and food prices. Wall Street and huge investment firms are artificially driving up the price of commodities, in some cases holding them off the market, and later dumping them, in order to skim-off huge profits – without lifting a finger… (3) Food Distributor and Retail Food Overhead – are also in an upward cost spiral, which has had a big impact on higher food prices. Big Conglomerate Food processors have reported record breaking profits – during and after rising food prices. So who’s telling you the truth? In a $4 box of corn flakes, there’s less than 10 cents worth of corn, and that’s not the same kind of corn that’s used to make ethanol…

…Conclusion: You don’t have to bash evolving corn ethanol or biodiesel, which is here NOW, displacing roughly 10 percent of dirty imported oil and driving down the cost of our fuel supply – in order to tout a breakthrough sugar eating fungi. I’m all for it – Just get your information right next time… Overall, I like the breakthrough content.

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