Diesel Fuel From a Tree Fungus?

[veggihatetank]

By Robert F. Service
ScienceNOW Daily News
3 November 2008
Petroleum geologists normally look for oil underground. Gary Strobel made his strike by pruning a tree. In the current issue of Microbiology, Strobel, a plant pathologist at Montana State University, Bozeman, and colleagues report that Gliocladium roseum--a novel fungus they discovered hidden within a stem from a scraggly tree in northern Patagonia--produces dozens of the same midlength hydrocarbons found in gasoline, diesel fuel, and jet fuel. The fungus may help companies convert the chemical energy stored in plants into liquid fuels capable of replacing fossil fuels.

The discovery is "a really great contribution," says Stephen Del Cardayre, a synthetic biologist and vice president for research and development at LS9, a South San Francisco-based start-up working to use microbes to produce renewable fuels. Even though the new fungus pumps out only small quantities of fuel hydrocarbons, researchers might use its genes to engineer other industrial microbes to do the job more efficiently. "The beauty is that even if the chemical reaction isn't perfect, you can always improve it," he says.

The search for fuel-producing microbes is one of the hottest areas in synthetic biology (Science, 24 October, p. 522). Strobel, an expert on endophytes--organisms that live within the tissues of other creatures--joined it by accident in 1997, when he discovered a fungus in Honduras that naturally produces volatile antibiotics, now being evaluated as a way to preserve fruit during shipping. Strobel has since identified related fungi around the globe that produce different volatile hydrocarbons. After discovering the new fungus wedged between cells in a stem from an Ulmo tree (Eucryphia cordifolia), Strobel and colleagues cultured the organism, collected the gaseous compounds it produced, and ran the compounds through a mass spectrometer to identify them. When he saw the printout, Strobel says, "every hair on my body stood up." The list included octane, 1-octene, heptane, 2-methyl, and hexadecane--all common components of diesel fuels.

Although other microbes are known to make individual volatile hydrocarbons common in fuels, Strobel says none can match the synthetic repertoire of G. roseum, which makes a staggering 55 volatile hydrocarbons: "No one has ever observed anything like this with any microbe before." He suspects that the fungus produces the hydrocarbon stew to inhibit other organisms from growing nearby.

Strobel and his colleagues also cultured G. roseum by feeding it cellulosic biomass like that from agricultural wastes, although the yield of volatile hydrocarbons declined. Even if the bug turns out not to produce fuels economically, Del Cardayre says, renewable-fuel companies are likely to try to adopt its synthetic prowess to boost the biofuel output of their own organisms, if they use similar metabolic pathways to convert energy-rich starting materials into hydrocarbons. Strobel is teaming up with his son, Scott, an enzymologist at Yale University, and members of his lab to sequence G. roseum's complete genome and identify its component enzymes.

Other energy-making bugs could be on the way, too. The younger Strobel says a recent sample-collection trip he made to South America with a group of Yale undergraduates found other novel endophytic fungi that turn out a wide variety of hydrocarbons. "There is just huge swaths of biodiversity to be discovered out there," Strobel says. That may persuade the next generation of oil explorers to trade in their seismographs for pruning shears.

[johnpierce79]

A tree fungus could provide green fuel that can be pumped directly into tanks, scientists say. The organism, found in the Patagonian rainforest, naturally produces a mixture of chemicals that is remarkably similar to diesel.
"This is the only organism that has ever been shown to produce such an important combination of fuel substances," said Gary Strobel, a plant scientist from Montana State University who led the work. "We were totally surprised to learn that it was making a plethora of hydrocarbons."
In principle, biofuels are attractive replacements for liquid fossil fuels used in transport that generate greenhouse gases. The European Union has set biofuel targets of 5.75% by 2010 and 10% by 2020. But critics say current biofuels scarcely reduce greenhouse gas emissions and cause food price rises and deforestation. Producing biofuels sustainably is now a target and this latest work has been greeted by experts as an encouraging step.
The fungus, called Gliocladium roseum and discovered growing inside the ulmo tree (Eucryphia cordifolia) in northern Patagonia, produces a range of long-chain hydrocarbon molecules that are virtually identical to the fuel-grade compounds in existing fossil fuels.
Details of the concoction, which Strobel calls "mycodiesel", will be published in the November issue of the journal Microbiology. "The results were totally unexpected and very exciting and almost every hair on my arms stood on end," said Strobel.
Many simple organisms, such as algae, are already known to make chemicals that are similar to the long-chain hydrocarbons present in transport fuel but, according to Strobel, none produce the explosive hydrocarbons with the high energy density of those in mycodiesel. Strobel said that the chemical mixture produced by his fungus could be used in a modern diesel engine without any modification.
Another advantage of the G. roseum fungus is its ability to eat up cellulose. This is a compound that, along with lignin, makes up the cell walls in plants and is indigestible by most animals. As such, it makes up much of the organic waste currently discarded, such as stalks and sawdust.

[awsrock]

Cool!

You would think that with all of these sources of possible biodiesel, that they would be able to just combine whatever amount they can produce to make available. That way, nobody could say "Well, this plant would be great, but we can't produce enough of it"
I feel like whoever decides on fuel sources is looking for a one-source solution