Scientists have created a synthetic version of a tiny, harmless virus in 14 days -- a significant step toward the goal of creating tailor-made life forms to chew up pollutants or provide novel fuels.
The work was conducted by a team at the Institute for Biological Energy Alternatives, a Rockville, Md., research group headed by Craig Venter, one of the leading figures in the sequencing of the human genome.
The virus was made by synthesizing many short strings of DNA using the molecule's fundamental chemical building blocks, then pasting them together in the correct order, the scientists said Thursday.
The viral DNA was inserted into bacteria, where it was able to replicate like a natural virus.
Last year, other scientists reported that they had successfully created the polio virus in a test tube, an undertaking that alarmed some scientists and ethicists. That effort took years instead of weeks.
The synthetic virus created by Venter's team, known as phi X174, infects only bacteria. Venter said the team chose to synthesize phi X174 because its genome is small. Also, its structure ensured stringent quality control: Its genes overlap with each other, and the synthetic virus would not have been able to invade cells and reproduce unless few or no mistakes were made during its creation.
The work, to be published in an upcoming issue of the Proceedings of the National Academy of Sciences, is one step toward a more ambitious goal of eventually creating an artificial, single-celled microbe 100 to 1,000 times larger than phi X174's 5386 nucleotides. This man-made bug would contain the minimal number of genes to support independent life.
Once created, the minimal microbe could be modified with extra genes, enabling it to perform useful jobs possibly including cleanup of such environmental pollutants as radioactive waste and smokestack emissions, or the production of fuels, such as methane and hydrogen.
There are already naturally occurring bacteria that possess such abilities, but they are not optimized for the task, Venter said.
"A lot of cells make hydrogen, but their goal in life is not to make it at a commercial level to power automobiles," he said. The natural bacteria would, however, provide a source for the needed genes, which could then be adjusted to maximize efficiency.
The research was funded by the Department of Energy.