Algae and more: Tomorrow’s cars and trucks could completely bypass petroleum. (© Ashley Cooper/Corbis) 

The Next Generation Of Biofuels

Americans burn through 140 billion gallons of gasoline a year. And even if drivers switch to more fuel-efficient cars and trucks, the nation’s fuel needs are expected to increase by a fifth over the next 20 years, thanks to dramatic increases in car and airplane use. Which is why—in addition to developing solar, wind and geothermal energy—policy makers, including President Barack Obama, are advocating biofuels to transform the transportation culture.

Among some of the most radical—and promising—ideas stirring within the biotechnology community today is the idea of making the equivalent of gasoline and diesel from the lowest life-forms on the totem pole: yeast, algae and bacteria. Such microorganisms could revolutionize our fuel infrastructure. One day you could swing by the local energy station and fill up on a microbe-made liquid from U.S. companies, not shipped from the Middle East. And even though biofuels release carbon dioxide when they are burned, the organisms they are made from draw an equivalent amount of carbon dioxide from the air—making biofuels essentially carbon neutral. The challenge is to make enough of these fuels economically and in a form compatible with today’s vehicles.

Pushing Pond Scum

J. Craig Venter, the entrepreneur and biologist whose Institute for Genomic Research in Rockville, Md., played a key role in mapping the human genome, argues strongly for this approach. He believes that the best biofuels will rely on algae and a few microorganisms that have a plantlike knack for directly and efficiently turning sunlight into energy through photosynthesis. The "most exciting" biofuel, he says, will be made from microbes that, when exposed to sunlight, consume carbon dioxide and turn it into energy directly—the equivalent of upgrading to a direct airline flight from one that had a long stopover. The idea might sound too good to be true, but Venter, who is known for his restless ambition, says it is possible.

The earth’s energy comes from the sun. An hour’s worth of sunlight holds enough power to meet a year’s worth of human energy needs. But less than a tenth of 1 percent of that energy is captured by plants. Venter and other scientists are experimenting with photosynthetic microbes such as algae and cyanobacteria (sometimes referred to as blue-green algae). Not only do these microbes remove carbon dioxide from the air, they also grow quickly—some forms double in just 12 hours, whereas grasses and other large plants can take weeks or months to do so. Photosynthetic microbes also store plenty of fat, which forms the basis for fuel. Biologist Willem Vermaas of Arizona State University recently engineered cyanobacteria to accumulate up to half their dry weight in fat. Just by opening up the cells, he can harvest the stored fats and convert them, in a few simple steps, into biofuel. Some plants, such as soybeans, also store fats and can be used as fuel sources, but Bruce Rittmann, Vermaas’s colleague at Arizona State, argues that photosynthetic microbes produce nearly 250 times more fat per acre.

The concept of algae-based fuel is not exactly new, and it’s fraught with problems. In 1978 the U.S. Department of Energy began trying to make biodiesel from algae, but the program ended 18 years later after the government concluded the concept wasn’t economically feasible. Algae and cyanobacteria are complicated critters. Although they can grow in open ponds, unwanted microbial strains can easily contaminate the water and interfere with the growth of the fuel-making strains. Venter’s alternative is to grow algae in transparent, outdoor vessels called photobioreactors, but these containers are expensive to build and maintain. They must also be constructed so that the right amount of sunlight hits them—too much or too little slows growth. What is more, harvesting the microbes and sucking out the stored fats requires environmentally unfriendly solvents, and new organisms have to be grown to replace the harvested ones.

Venter says that his newest company, Synthetic Genomics in La Jolla, Calif., is well on its way to overcoming one of the hurdles: His microbes can be reused multiple times because he has engineered them to release fat rather than store it. In addition, he has found a way to prevent the unwanted spread of these organisms should they ever be accidentally released from a facility; they can survive only if they are fed a chemical they cannot produce on their own. Synthetic Genomics will soon be testing the approach on a commercial level. "We’ve had some really major breakthroughs," Venter says.

Hedged Bets In A High-Stakes Game

Other companies are well on their way, too. San Diego biotech firm Sapphire Energy claims it could be selling gasoline made from algae by 2011. Solix Biofuels, a start-up based in Fort Collins, Colo., plans to have its first pilot facility running by this summer. "A lot of people said we’d never fly, we’d never walk on the moon, the light bulb would never work. What it takes is a lot of discipline and diligence to move forward," says Rich Schoonover, Solix’s chief operating officer.

According to Samir Kaul, a partner at Khosla Ventures, a San Francisco Bay Area venture-capital firm, the companies that survive will be the ones whose fuels can compete with oil at $40 a barrel. Venter agrees: "I think that’s going to end up being the biggest challenge: Can we build these really large facilities and do it in a cost-effective, environmentally friendly way?" It’s a high-stakes game, and even the scientists are hedging their bets; some of Venter’s projects involve producing fuels from plants instead.

Ultimately, whoever produces abundant biofuels could end up making more than just big bucks—they will make history. "The companies, the countries, that succeed in this will be the economic winners of the next age to the same extent that the oil-rich nations are today," Venter says. He even suggests, in his characteristically unabashed way, that those companies and nations could end up igniting a second industrial revolution—one fueled by the need to undo the environmental consequences of the first.