Keasling scored his first major breakthrough in the synthetic biology field in 2003 when he and his colleagues reported that by transplanting genes from yeast and the sweet wormwood tree (Artemsisia annua) into E. coli bacteria, then by-passing the E. coli's metabolic pathway and engineering a new one based on the mevalonate pathway in yeast, they were able to induce the bacteria to produce a chemical precursor to artemisinin, the world's most powerful drug for treating malaria.
In 2004, Keasling received a $42.6 million grant from the Bill and Melinda Gates Foundation, through the Institute for OneWorld Health, a San Francisco-based nonprofit pharmaceutical company, to further develop his microbial artemisinin technology. This led to a partnership with Amyris, a biotech start-up co-founded by Keasling, that engineered a strain of yeast (Saccharomyces cerevisiae) capable of producing high levels of artemisinic acid, the immediate precursor to artemisinin. Today, the pharmaceutical company Sanofi-Aventis is poised to provide mass-produced low-cost microbial-based artemisinin that will stabilize supplies and prices and make the drug far more accessible for those who need it most.
Artemisinin is the key component in artemisinin-based combination therapies (ACTs), which are the World Health Organization's recommended first-line treatment for malaria. Currently, artemisinin is extracted from sweet wormwood, a fern-like plant grown mostly in China and Vietnam, and manufactured through costly chemical synthesis. Weather and other conditions have led to fluctuating prices and drug shortages. According to the World Health Organization, each year nearly 500 million people become infected with malaria, and nearly three million, mostly children, die from it.
For his breakthrough with artemisinin, Keasling in 2009 received the first Biotech
|Contact: Lynn Yarris|
DOE/Lawrence Berkeley National Laboratory