11-13: Production of Terpene Based biofuels in S. cerevisiae

The generation of microorganisms that can produce biofuels similar to petroleum-based transportation fuels would allow the use of existing engines and fuel transportation infrastructure. The corrosivity and high hygroscopicity of ethanol, today’s preferred biofuel, are incompatible with existing technologies. “Second generation” biofuels should have better physical properties than ethanol and a higher energy content per unit. Here, a Saccharomyces cerevisiae platform previously engineered to overproduce farnesyl pyrophosphate has been adapted to produce a variety of terpenoid base biofuels.  First, a series of terpene synthases were tested for the production of monocyclic, bicyclic, and linear sesquiterpenes in yeast. Next, the production levels of the different sesquiterpenes were optimized and the molecules classified based on their structure and yield as potential biofuel candidates. Finally, the terpene synthases leading to the most promising biofuel candidates were introduced in Escheria coli able to overproduce farnesyl pyrophosphate and tested for biofuel production. This is the first time that such a large array of terpene synthases has been tested for the production of sesquiterpenes in S. cerevisiae. Importantly, some of the successfully produced sesquiterpenes have structures similar to gasoline and jet fuel and may be useful second generation biofuels.