Engineering Photosynthetic Cyanobacteria to Produce the Energy-Dense Fuel Farnesene from Carbon Dioxide

The goal of the project is to genetically engineer photosynthetic cyanobacteria that will synthesize farnesene from carbon dioxide. The work will then involve shutting down pathways that compete for carbon in an attempt to maximize the amount of farnesene that can be produced. Then we will do tolerance testing by culturing the cyanobacteria in varying concentrations of the end product(s) in order to determine the optimal culturing conditions. This work will develop an engineered cyanobacterium capable of converting CO2 into farnesene (C15H24), a long-chain hydrocarbon with an energy density of 47 MJ/Kg, heat of vaporization of 0.24 MJ/Kg, and octane of 89.7. The cells would excrete farnesene into the recirculating culture fluid, where it would be recovered by low-cost phase separation for use as an energy-dense, infrastructure compatible biofuel. We have already established the validity of this "cyanofactory" platform by engineering Anabaena to produce the ten-carbon alcohol linalool. Farnesene has a much higher energy density and thus would be a more desirable 3rd generation biofuel.