In a bid to take the lead in algae-based biofuels, ExxonMobil will plow $600 million into genome guru Craig Venter's company Synthetic Genomics and plans to construct a pilot facility in San Diego.

"This is the largest—to our knowledge—single investment in really trying to produce biofuels," Venter said in a telephone conference this morning. Venter is the hard-charging geneticist best known for running the private venture that sequenced the human genome. In 2005 he founded Synthetic Genomics to apply the tools of genetics to environmental and energy problems.

The company has genetically engineered photosynthetic algae, including cyanobacteria and single-celled microalgae, to use sunlight to convert carbon dioxide directly into long-chain hydrocarbons that can be processed for diesel, gasoline and other transportation fuels. Venter plans to pipe in the carbon dioxide from power plants or refineries.

With more than 100 algae companies competing in the biofuel sector, he has some stiff competition.  Indeed one industry leader, GreenFuel Technologies, closed shop in May. Most of these algal biofuel outfits must either dispose of the green muck left over from fuel extraction process or market it as cattle feed or fertilizer.

Venter claims to be able to turn algal cells into tiny factories that continuously secrete fuel, which cuts down on waste. The company's algae are currently 10 times more efficient per acre than corn-based biofuels and three times more efficient than palm oil plantations. Even so, Venter said the ExxonMobil deal also calls for further research to optimize the algae strain and build a "greenhouse facility" for growing the algae "very soon."

But Jane Rissler, an expert in agriculture biotechnology at the left-leaning advocacy group Union of Concerned Scientists isn't holding her breath. "It would be prudent to have a great deal of skepticism about the ultimate success of this," she says. "As you add more genes and more manipulations—at least in plants—it seems to reduce the degree of success."

A separate concern, Rissler says, is the potential environmental impact of large-scale agriculture of genetically engineered petroleum-producing algae, either in contained bioreactors or open ponds, particularly when the effort is spearheaded by a multinational corporation not known for its ecological stewardship. "I think one would almost have to assume that some [algae] would be released in the environment," she says. "It becomes a serious risk that would need to be fully assessed."

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