Termite Guts May Hold Key to Better Biofuels

Ben Hirschler, PlanetArk 22 Nov 07;

"Good food is today being turned into fuel instead of being fed to people. If we could make ethanol from wood waste instead that would clearly be a good thing,"

LONDON - The back-end of a termite is an odd place to look to solve the world's energy crisis but scientists believe the insects' guts may hold the key to better and cheaper biofuels.

Researchers said on Wednesday they had identified a rich reservoir of wood-digesting enzymes exuded by bacteria living in the bellies of termites.

The efficient processes the insects use to turn wood into food could one day be harnessed in factories to transform wood into fuel for transport as an alternative to crops like corn.

The discovery follows a genome-wide analysis of bacteria from the hindgut of the Nasutitermes termite species in Costa Rica, published in the science journal Nature.

Soaring oil prices and concerns about climate change have triggered a boom in biofuels produced from renewable resources like sugar, corn and soybeans.

But making gasoline substitutes from wood -- a plentiful but tougher biomass source -- has so far proved elusive.

Termites, whose voracious appetite for wood causes massive damage to homes worldwide, have no such problems. In fact, their intestines are astonishingly efficient bioreactors, or chemical processing chambers.

Now the secret of how they convert wood into sugars is starting to be unlocked by scientists from the US Department of Energy Joint Genome Institute, the California Institute of Technology and biotechnology company Verenium Corp.

Scientist Falk Warnecke and colleagues used industrial-scale DNA sequencing to show that the guts of termites contain a huge range of bacterial genes responsible for making many previously unknown enzymes.

The next step will be to figure out the precise role of these enzymes and eventually to synthesise them for use in engineering schemes that can convert wood into biofuels, such as hydrogen or ethanol.

The potential is considerable, given the sheer efficiency of the termite's intestines, which can theoretically turn one sheet of paper into two litres of hydrogen, according to Andreas Brune of the Max Planck Institute for Terrestrial Microbiology in Marburg, Germany.

"Good food is today being turned into fuel instead of being fed to people. If we could make ethanol from wood waste instead that would clearly be a good thing," Brune said. (Reporting by Ben Hirschler; Editing by Elisabeth O'Leary)

Fuel's gold: Termites point way to new dawn of bio-energy
Yahoo News 22 Nov 07;

A team of US scientists poring over the intestines of a tropical termite have a gut feeling that a breakthrough in the quest for cleaner, renewable petrol is in store.

Tucked in the termite's nether regions, they say, is a treasure trove of enzymes that could make next-generation biofuels, replacing fossil fuels that are dirty, pricey or laden with geopolitical risk.

Termites are typically a curse, inflicting billions of dollars in damage each year by munching through household timber with silent, relentless ease.

But gene researchers say the hind gut of a species of Central American termite "harbour a potential gold mine" of microbes which exude enzymes to smoothly break down woody fibres and provide the insect with its nutrition.

Present-generation biofuels are derived from corn, sugar and other crops, whose starch is converted into ethanol by enzymes, fermentation and distillation.

One of the problems, though, is that this product entails converting food into fuel. Hefty US subsidies to promote bio-ethanol is having price repercussions across swathes of the global food market.

Next-generation biofuels, though, would use non-food cellulose materials, such as wood chips and straw. But these novel processes, hampered by costs and complications, are struggling to reach a commercial scale.

The termite's tummy, though, could make all the difference.

Like cows, termites have a series of intestinal compartments that each nurture a distinct community of microbes.

Each compartment does a different job in the process to convert woody polymers into the kind of sugars that can then be fermented into biofuel.

The US team has now sequenced and analyzed the genetic code of some of these microbes in a key step towards -- hopefully -- reproducing the termite's miniature bioreactor on an industrial scale.

Their work, published on Wednesday in Nature, required scientists to venture into the rainforests of Costa Rica, where they plucked bulbous-headed worker termites from a large nest at the foot of a tree.

Using fine forceps and needles, they extracted the contents of the third paunch, or hind gut, from 165 termites, and sent this to a lab in California for sequencing.

From this, some 71 million "letters" of genetic code emerged, pointing to two major bacterial lineages called fibrobacters, which degrade cellulose, and treponemes, which convert the result to fermentable sugars.

Termite guts are incredibly efficient, said Andreas Brune of the Max Planck Institute for Terrestrial Microbiology in Marburg, Germany.

"In theory, they could transform an A4-sized sheet of paper into two liters (1.8 pints) of hydrogen," he said.

Eddy Rubin, director of the Joint Genome Institute (JGI), an organisation that comes under the aegis of the US Department of Energy, said an important fundamental step had been made, even if a long road still lay ahead.

"Scaling up this process so that biomass factories can produce biofuels more efficiently and economically is another story," said Rubin.

"To get there, we must define the set of genes with key functional attributes for the breakdown of cellulose and this study represents an essential step along that path."

Other scientists taking part in the project were from the California Institute of Technology (Caltech), biofuels company Verenium Corp., the National Biodiversity Institute (INBio) of Costa Rica and the IBM Thomas J. Watson Research Center.