The team started with the bacterium M. genitalium, an obligate intracellular parasite whose genome consists of 482 genes and 580,000 base pairs, arranged on one circular chromosome (the smallest genome of any known natural organism that can be grown in free culture). They then systematically removed genes to find a minimal set of genes that can sustain life. This effort was also known as the Minimal Genome Project.
The team intends to synthesize chromosome DNA sequences consisting of these 381 genes. In 2003, the team had demonstrated a fast method of synthesizing a genome from scratch, producing the 5386-base genome of the bacteriophage Phi X 174 in about two weeks. However, the genome of M. laboratorium is about 50 times larger. In January 2008, the team reported to have synthesized the complete 580,000 base pair chromosome of M. genitalium, with small modifications so that it won't be infectious and can be distinguished from the wild type. They named this genome Mycoplasma genitalium JCVI-1.0.
Once a version of the minimal 381-gene chromosome has been synthesized, it is intended to be transplanted into the nucleoid of a M. genitalium cell to create M. laboratorium. The team had demonstrated the process of transplanting a (non-synthetic) genome from one Mycoplasma species to another in June 2007.
The resulting M. laboratorium bacterium is expected to be able to replicate itself with its man-made DNA, making it the most synthetic organism to date, although the molecular machinery and chemical environment that would allow it to replicate would not be synthetic.
The J. Craig Venter Institute filed patents for the Mycoplasma laboratorium genome (the "minimal bacterial genome") in the U.S. and internationally in 2006. This extension of the domain of biological patents is being challenged by the watchdog organization Action Group on Erosion, Technology and Concentration.
Venter hopes to eventually synthesize bacteria to manufacture hydrogen and biofuels, and also to absorb carbon dioxide and other greenhouse gases. George Church, another pioneer in synthetic biology, holds that E. coli is a more efficient organism than M. genitalium and that creating a fully synthetic genome is not necessary and too costly for such tasks; he points out that synthetic genes have already been incorporated into E.coli to perform some of the above tasks.