Short communicationCoupled CO2 fixation from ethylene oxide off-gas with bio-based succinic acid production by engineered recombinant Escherichia coli

- Succinate-producing E. coli was used to fix CO2 from ethylene oxide off-gas.
- Acetaldehyde was the main factor inhibiting cell metabolic capability.
- irrE gene was introduced to improve cell resistance to acetaldehyde.
- A novel approach to fix CO2 from industrial exhaust gases was established.

Industrial exhaust gases contributed heavily to anthropogenic CO2 emissions. In this study, a novel approach of capturing CO2 from ethylene oxide off-gas and converting it into a platform C4 chemical was established by using succinate-producing E. coli. Fermentation results showed that the acetaldehyde in the off-gas was the main factor inhibiting cell metabolic capability, thus IrrE which is a global regulator from Deinococcus radiodurans was used to improve cell resistance to acetaldehyde. A final succinic acid titer of 68.12 g L−1 with a CO2 fixation rate of 4.7 mmol L−1 h−1 was achieved. Notably, this coupled process not only realized the CO2 fixation from ethylene oxide off-gas but also provided a potential cost-effective gas source which holds potential application for bio-based succinate production.