Scientists have synthesized the entire genome of a living organism — a bacterium — an accomplishment they say could lead to the development of artificial life.

The entire genome of the bacterium Mycoplasma genitalium is only 485 working genes, the smallest of any living organism that can replicate by itself. But researchers at the J. Craig Venter Institute in Rockville, Md., said the process could eventually be applied to create synthetic organisms capable of producing biofuels or cleaning up toxic waste spills.

In research to be published in the Jan. 25 issue of the journal Science, the scientists described the process by which they created the genome from scratch, using E. coli bacteria to store copies of artificial chromosomes and then assembling the larger pieces together in yeast.

Researcher Hamilton Smith, speaking to Science, said the next step will be to see if the newly synthesized genome can be placed inside another cell to activate further production of the bacterium. Only once the genome proves it can work within a host cell will the potential applications of the technology be realized, said Smith.

"I liken the process to how a computer works," he said. "You have an operating system which by itself doesn't do anything, but when you install it on a computer then you have a working computer system."

"It's the same with the genome, the genome is the operating system for the cell, and the cytoplasm [in the cell] is the hardware that's required to run that operating system. The two together make a living, producing cell."

The researchers said the process could be used to reprogram potentially harmful bacterium like M. genitalium — which can cause sexually transmitted infection in men and women — into microorganisms capable of performing more useful tasks.

The same researchers made news last summer when they published results from a similar experiment, successfully swapping a genome from one bacterium to another in what they called the first "genome transplant."