Life 2.0

So far, researchers have fabricated individual biological building blocks, but they have yet to create an entirely new synthetic self-replicating organism. "Chemical synthesis of life has been a standing challenge to synthetic organic chemistry," says Venter (with palpable impatience). But SynBio researchers see no reason to wait until whole organisms can be created from scratch. They are happy to stitch together lab-designed biological components, or "biodevices," with parts of natural cells to construct hybrid organisms. The SynBio enterprise is not some ivory-tower exercise but a pragmatic field that could soon produce results. Church, who at 53 is an elder SynBio guru, thinks it could happen as soon as two years from now if funding is ramped up and scientists don't run into major snags.

Since June 2004, when MIT hosted the first international Synthetic Biology conference, researchers have designed and fabricated thousands of programmable biodevices—bits of genetic machinery that can be brought together to carry out more-sophisticated tasks. Biodevices could conceivably have enormous advantages over traditional manufacturing processes and sources of material. Cell machinery could operate the equivalent of multistep production lines at the molecular level, fabricating complex chemical products precisely, atom by atom. They would also work cheaply and efficiently, fed by simple safe substances like sugar. And once a biodevice is designed and properly fabricated, the hard work is over—its users can instruct it to make as many copies of itself, by itself, as are needed. Biodevices could churn out any imaginable pharmaceutical drug, including ones that are impossible to produce by traditional chemistry, or are prohibitively expensive today. Similarly, they could create any other kind of chemical or polymer for the production of plastics, real wool or silk—at a fraction of today's costs—or other structural and functional materials that have yet to be conceived. Other biodevices could act as sensitive environmental biosensors, programmed to detect and degrade specific toxic organisms, such as anthrax, or to glow in the proximity of a biological, chemical or radiological weapon.

A few projects are already giving us a glimpse of the power of this new field. The most extraordinary effort is to create a microbial organism that would produce a powerful antimalarial drug. In the past, the quinine class of drugs had been effective in treating malaria, but resistant parasite strains have been gaining ground. Artemisinin, a product of the sweet wormwood tree, is a highly effective treatment for people with quinine-resistant malaria, but it cannot be produced in large quantities. In 2004, Keasling, the Berkeley chemical engineer, persuaded the Bill and Melinda Gates Foundation to give him $42 million for the project.

Keasling began with common baker's yeast. Evolution has "programmed" the yeast—by bestowing it with certain genes—to process sugar (its food) along a step-by-step metabolic pathway that results in the various biochemicals required for life. Into this already functioning organism, he added a lab-designed genetic software program made up of 12 new genes. The genetic program diverts a portion of the yeast's metabolism down to a completely new biochemical pathway that results in the chemical synthesis of artemisinin. In April 2006, Keasling announced that he was just one step away from the final compound, and on target to reach the finish line before 2009. Once he's done that, some sugar and a bit of yeast in a fermentation tank could be a cheap and efficient source of enough artemisinin to treat all the malaria cases in the world. Says Keasling: "We're building the modern chemical factories of the future."

Christopher Voigt, of UC San Francisco, and Christina Smolke, of Caltech, are in the early stages of designing microbes that would circulate through the human bloodstream, seeking out cancerous tumors anywhere in the body. The microbes might be equipped with a biodevice that detects the low oxygen levels characteristic of a tumor, another that invades the cancer cells, a third that generates a toxin to kill the cells and a fourth that hangs around afterward in case the cancer comes back. All this would happen without the patient's even knowing. Eventually, circulating cellular sentries could monitor and adjust blood levels of critical substances including glucose and cholesterol.

Venter and Church are eyeing an even bigger prize: a self-sustaining, highly efficient biological organism that converts sunlight directly into clean biofuel, with minimal environmental impact and zero net release of greenhouse gases. What would an ideal biofuel-generation system look like? "The most sustainable source of energy is sunlight and the most convenient products are pipeline-compatible petrochemicals," says Church. "So I would aim for a perennial plant system that secreted pure chemicals—octane, diesel, monomer for plastics, etc.—into pipes without need for further purification."