earticle

영어

Strategies for environmental-friendly reduction of CO2 to organic compounds have gained worldwide attention due to the growing consensus that increasing emissions of CO2 are causing global warming. The efficient utilization of CO2 will not only help to alleviate greenhouse effect, but also to obtain useful chemicals as well. In this work, biocatalytic reduction of CO2 by formate dehydrogenase (FDH) was investigated. In order to improve the catalytic stability of FDH, the enzyme was immobilized through cross-linked enzyme aggregates (CLEAs). The optimal conditions for the preparation of CLEAs were determined by changing kinds and concentration of cross-linker. Bovine serum albumin (BSA) was also used as a proteic feeder to increase the immobilization yield. The recovered activities of CLEAs were highly dependent on the concentration of glutaraldehyde, while the recovered activity was not severely influenced by the content of dextran polyaldehyde as a mild cross-linker. The recovered activity of CLEAs was about 18% under optimized conditions. The residual activity of FDH CLEAs cross-linked with dextran polyaldehyde (Dex-CLEAs) was over 95% after 10 times reuse. Thermal stability of Dex-CLEAs was 3.4 times enhanced compared with free enzyme. CLEAs of FDH could reduce CO2 to formate with very low reduction of activity after repeated use.