Tackling resistance

BERKELEY, Calif.—Multidrug-resistance is increasing in world efforts to tackle malaria, and this problem is only exacerbated by the short supply and high cost of the antimalarial drug artemisinin. To address this problem, scientists at the University of California, Berkeley and Amyris Biotechnologies developed a method to biosynthetically produce high yields of artemisinin precursors in yeast, offsetting some of the associated costs of arteminisin production. They described their efforts in Nature (2006, 440, 940-943).

The researchers modified and co-opted the natural metabolic pathways of Saccharomyces cerevisiae to refocus the microbe's cellular machinery on the production of amorphadiene and artesiminic acid, two key precursors to the drug. Because they found most of the compounds in the cellular pellet upon lysis, they were able to develop a single-step column separation that produced >95 percent pure artemisinic acid. The transgenic yeast produced the precursor at levels matching that produced naturally by the plant Artemisia annua but in the time course of days as opposed to months.