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09|08|2011 - 08h43No Eureka Moments in U.S. to Crack Cellulosic Code

Fourth in an occasional series on the bioeconomy.

By NYT
Paul Voosen

Down on a farm in Illinois, his forearm stuck inside the noisome gut of a living and otherwise unperturbed brown cow, Matthias Hess, a German-born microbiologist and geneticist, felt far removed from the white hum of his biology lab. 

Hess had been fishing in the cow's rumen, its largest stomach, for a nylon mesh sack resembling an oversized teabag. The stink of vomit mixed with rotten eggs and fertilizer. Working through a permanent rubberized hole carved into the heifer's side, Hess waited for its half-digested slop to churn, freeing his hand. Then he pulled out the teabag, which three days earlier he had stuffed with pulverized prairie grass.

The rumen is like a huge bathtub, he said, holding about 50 large soda bottles' worth of fluid redolent with bacteria. Relying on these symbiotic microbes, cows eat up to 150 pounds of grass a day, a food inedible to most animals, including humans. Hess was after those microbial secrets, and the placid heifer was happy to oblige.

"You can just do your experiment," he said later. "The cows don't really care."

Unglamorous as it may sound, Hess and his fellow researchers are at the forefront of one of the defining scientific pursuits of our time. It's a hunt that, if successful, could reshape the world's landscape, sending biofuel prices through the floor and allowing a drastic reduction in the country's oil use. It's a long campaign, and the opposition is all around.

It is a war, at its most fundamental, against plants.

For eons, plants have locked the sun's energy into complex strands of sugar, used to build their stems and leaves. These chains are far different from table sugar or grain starch; they cling together, providing the meat of tree trunks and cotton strands. They are the most abundant organic material on the planet, and one of the most hunted.

As long as plants have built up these complex sugars, life in all its forms, from microbes to mastodons, has sought ways to unleash that energy. Since plants can't run, and live for hundreds of years, they have built remarkable defenses, wrapping their cellulose, as the sugars are called, in a sort of barbed wire that, to this day, defies human degradation.

From a series of low-slung buildings in Walnut Creek, Calif., east of Oakland and nestled at the base of Mount Diablo, the Department of Energy's Joint Genome Institute (JGI), fresh from sequencing the human genome, has pursued for the past half-decade the DNA of microbes known to unwind these barbed wires. Marshaling these genetic resources is one of the institute's top priorities, on parallel with its cancer research.

It may sound strange, but the cellulose work is like Lewis Caroll's "Through the Looking-Glass," said Eddy Rubin, JGI's director and Hess' former boss. At one point, Alice hustles after the Red Queen, but she never gains any ground. Likewise, plants have kept their lead over all comers, Rubin said.

"It's been this Red Queen kind of event," he said. "This molecule has evolved ways to prevent water and pests from getting in. It's kept on building new structures. ... These plants have evolved for tens of millions of years to prevent their breakdown."

If biofuels are going to make up a large amount of of the U.S. fuel mix, scientists will need to chase down this Red Queen. Only then can the incipient bioeconomy, now based on energy-intensive corn, decouple from its competition with food. At their most hopeful, scientists envision fields of ultra-productive grasses and trees growing on degraded land, the plants providing the energy for a new American century.

It's a vision that has existed for decades. And a dream that won't be easily reached.

Skeptical about mandates

A new modesty has descended on the biofuel world. Several years ago, overconfident researchers and policymakers predicted that they would soon develop tools to cheaply break down plant walls, creating "cellulosic" ethanol. These predictions begat policy, with congressional biofuel mandates, passed in 2007, calling for 250 million gallons of cellulosic ethanol to be used this year, rising to 500 million gallons in 2012.

For more news on energy and the environment, visit www.greenwire.com.
Greenwire is published by Environment & Energy Publishing

 


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