The drug, artemisinin, is one of the most promising next-generation antimalarials because of its effectiveness against strains of the malaria parasite now resistant to front-line drugs. It is now too expensive for broad use in countries such as Africa where it is most needed.
"By inserting these genes into bacteria, we've given them the ability to make artemisinin quickly, efficiently and cheaply, and in an environmentally friendly way," said Jay D. Keasling, professor of chemical engineering at UC Berkeley. His research is being published online June 1 in Nature Biotechnology and is scheduled to run in the journal's printed edition in July.
Keasling's technique for transplanting yeast and plant genes to construct an entirely new metabolic pathway inside bacteria can be used generally to produce a broad family of so-called isoprenoids -- chemical precursors to many plant-derived drugs and chemicals of interest to industry, including the anticancer drug taxol and various food additives. Isoprenoids, found widely in microbes, plants and marine organisms, currently are very expensive for the chemical industry to synthesize from scratch and nearly as expensive to extract from plant material.
"This process could be of interest to everybody -- drug companies making cancer agents, the government producing antibiotics against bioterror agents, or industries making flavors and fragrances," Keasling said. "A company could tweak the bacteria a bit, adding any number of plant genes involved in making the chemical of interest, to get pretty much any isoprenoid. It would be easy to do now."