APPLICATIONS OF TECHNOLOGY:
- Biofuel production
- Other fermentative processes used for chemical production
- Efficiently addresses long term storage issues of isoprenoid-based biofuels
- Regenerates NAD+ more cost effectively to maintain redox balance in biofuel-producing host strains
- Could increase product yield
Researchers at the Joint BioEnergy Institute (JBEI) have developed technology to reduce the hydrocarbon double bonds in isoprenoid-based biofuels, bonds that make these fuels susceptible to long-term storage problems, by engineering a gernanylgeranyl reductase (GGR) from the archaeon Sulfolobus acidocaldarius to reduce isoprenoids, using NADH as a cofactor. The enzymes may also be engineered to reduce hydrocarbon double bonds on unbranched fatty acid tails.
Hydrocarbon bonds in biodiesels will either form cross-links or react with atmospheric oxygen to form peroxides that degrade the rest of the molecule, an issue of particular importance for potential isoprenoid-based biofuels due to the double bonds in isoprenoids. In addition, an excess of NADH is formed due to the fermentation conditions of the reactions to produce these biofuels, and NAD+ must be regenerated by either the costly addition of oxygen or the sacrificial reduction of pyruvate with NADH, lowering product yield. With the Berkeley Lab technology, less carbon flux would be diverted away from production pathways to regenerate NAD+, potentially increasing product yield.
Double bonds in fuels are currently removed through an additional catalytic hydrogenation step using hydrogen gas, adding material and energy expenses.
DEVELOPMENT STAGE: Proven principle.
STATUS: Available for collaborative research.
REFERENCE NUMBER: EIB-2867
The Joint BioEnergy Institute (JBEI, www.jbei.org) is a scientific partnership led by the Lawrence Berkeley National Laboratory and including the Sandia National Laboratories, the University of California campuses of Berkeley and Davis, the Carnegie Institution for Science and the Lawrence Livermore National Laboratory. JBEI’s primary scientific mission is to advance the development of the next generation of biofuels.