Researchers look to termites in bid to find biofuels for cars

As oil companies scour the globe for new drilling spots, microbiologists are looking for the keys to an energy revolution — inside termites from the jungles of Costa Rica.

The head of the federal Joint Genome Institute in Walnut Creek reported Friday at one of the world’s largest scientific conferences that his researchers are closing in on the genes that enable bacteria-packed termites to turn woody plant materials into sugars, natural gas and hydrogen.

If the effort succeeds, biotech companies could use the information to grow new enzymes and modified germs to churn out enormous quantities of biofuels burnable in automotive engines.

“I think in 10 years we’re going to see significant percentages of the transportation fuel replaced” by biologically produced fuels, said Eddy Rubin, director of the institute, established by three federal laboratories operated by the University of California.

Decoding the DNA inside the guts of termites is a small but critical step in shifting from fossil fuels — storing solar energy gathered by plants thousands of years ago — to biofuels that store solar energy from the last growing season.

One of the costliest elements in producing biofuels is the enzymes needed to break down the structural materials of plant, called lignocellulose, and turn it efficiently into sugars that can be fermented into fuel, such as ethanol.

Termites do this easily, aided by several hundred kinds of bacteria living in their guts. To explore that symbiotic relationship, scientists are diving into the viscous brown world where plants are destroyed and a whole society of germs feed themselves, as well as the termite.

“It’s like toothpaste. It’s full of wood fibers and particles,” said Falk Warnecke, a microbiologist in the institute’s microbial ecology program. Its scientists work with colleagues at Caltech and Diversa, a San Diego company specializing in building DNA libraries from the natural world for human commercial use.

“It’s a very interesting system from a biological point of view,” Warnecke said. “The insect provides a very regulated bioreactor to the microbes, and they provide some necessary substrates for the insect. They couldn’t live without each other.”

So far, scientists only have sequenced a small fraction of the vast DNA soup inside the termites. They rely on “shotgun” sequencing to gather snippets of DNA from many bacteria at the same time, then try to piece them back together and identify which ones supply the genes that are most useful for converting lignocellulose to sugar.

“These termites have lots and lots of different bugs in their intestines, so we’ll be doing this for a while,” Rubin said Friday from St. Louis, site of the American Association for the Advancement of Science’s annual meeting.

It is unlikely that scientists will identify all of the organisms inside the termite, but within the next year they expect to identify many of the wood-devouring genes. Biotech firms are poised to add those genes to other microorganisms that, unlike those in the termite, can be raised by humans.

“These bacteria are not culturable in the laboratory so far,” Warnecke said. “We don’t have the right tools despite hundreds of years of microbiology experience.”

He isn’t sure how successful the decoding effort will be but says the rewards could be substantial.

“It’s a very nice assumption that we can at least consider a solution to the energy crisis, to replace the fossil fuels with biomass-derived fuels,” he said.

Source

Inside Bay Area Feb. 18, 2006.

Share