APPLICATIONS OF TECHNOLOGY:
- Integrated volatile capture and conversion of isoprenol for fuels and bio-based products
- Isoprenol toxicity is overcome via gas stripping
- Isoprenol can be captured and converted to isoprene safely, with high efficiency, no required distillation
- Enables >90% recovery
- Both isoprenol and isoprene are potentially high volume biochemicals accessible via high flux metabolic pathways. However, the biological production of isoprenol and isoprene is limited by product toxicity and flammability / off-gas capture challenges.
In this invention, aeration used to supply oxygen to the bioreactor is leveraged to strip isoprenol to the fermentor off-gas, ensuring aqueous concentrations below the toxicity threshold. As compared to isoprene, the higher boiling point of isoprenol enables relatively facile recovery via stripping to either chilled organic solvent or chilled water. To avoid saturation, this capture medium must be regenerated by removing the isoprene. Rather than typical recovery via distillation, in this system aqueous isoprenol is continuously dehydrated to isoprene, which is then recovered in relatively pure form as a gas. The resulting purified water is then recycled to the off-gas capture system, as either a direct capture medium, or as a stripping solvent for the capture medium in liquid-liquid extraction.
The approach has yielded titers of 20 g/L, in this case from an E. coli strain, the highest titers for isoprenol production to date, and double what has been achieved with in situ extractive fermentation. It overcomes toxicity, has a lower cost recovery, and uses existing aeration.
While current production of isoprene relies on petrochemical feedstocks, this novel route creates a robust alternative that overcomes the critical challenges in biological isoprene production: product flammability and capture efficiency. In addition, it could enable scaled production of bio-isoprene for conversion to a sustainable advanced performance aviation fuel, dimethylcyclooctane.
DEVELOPMENT STAGE: Proven principle
STATUS: Patent pending.
OPPORTUNITIES: Available for licensing or collaborative research.
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