Chemicals from Microbes
A sustainable method to make high-value chemicals from sugar was invented at Genomatica. In addition to refining crude oil into gasoline for automobiles, refineries “crack” or process crude oil into higher-value industrial chemicals such as 1,4-butanediol (BDO) and methyl ethyl ketone (MEK). Genomatica has discovered a way to make both these chemicals from sugar in microorganisms, bypassing the need for oil.
Started in 2000, Genomatica first created and sold computational software to model how cells function and their metabolic pathways. “In the past two to three years, we used our computational models to design microbes to make chemicals,” says Christophe Schilling, Ph.D., president.
In September 2008, Genomatica reported on a biomanufacturing process for BDO in Escherichia coli that starts with sucrose. With its computational modeling software, the company’s researchers examined all possible biological pathways for making BDO from sugar (about 40,000), then they selected the best pathway and enzymes. After genetically engineering six enzymes into E. coli, the microbe generated BDO within six months. “E. coli or any other organism was never known to make BDO before,” explains Dr. Schilling.
The microbe-based process is designed to make BDO at a lower cost than petroleum-based methods. Since the results were made public, three-quarters of BDO producers worldwide have contacted Genomatica to learn about the method, according to Dr. Schilling. “Producers find it appealing to start with a renewable source and like the environmentally friendly angle,” he adds. The method has been scaled up in the laboratory to 30 L volumes and a demonstration plant is planned for large-scale fermentation. BDO, a precursor of Spandex fibers and thermoplastics, has a worldwide annual production value of $4 billion.
A similar computational modeling method led to the generation of MEK from sugar in bacteria, which the company reported in February. MEK is a common solvent in paints and varnishes, and its global market is valued at $2 billion. Moreover, the sustainable chemical processes for making MEK can be readily transferred to equipment at bioethanol manufacturing facilities, some of which have been left idle by recent market contraction.