Production,purification, and characterization of a fusion protein of carbonic anhydrase from Neisseria gonorrhoeae and cellulose binding domain from Clostridium thermocellum

Carbon dioxide capture technologies have the potential to become an important climate change mitigation option through sequestration of gaseous CO₂. A new concept for CO₂ capture involves use of immobilized carbonic anhydrase (CA) that catalyzes the reversible hydration of CO₂ to HCO₃^? and H⁺. Cost‐efficient production of the enzyme and an inexpensive immobilization system are critical for development of economically feasible CA‐based CO₂ capture processes. An artificial, bifunctional enzyme containing CA from Neisseria gonorrhoeae and a cellulose binding domain (CBD) from Clostridium thermocellum was constructed with a His₆ tag. The chimeric enzyme exhibited both CA activity and CBD binding affinity. This fusion enzyme is of particular interest due to its binding affinity for cellulose and retained CA activity, which could serve as the basis for improved technology to capture CO₂ from flue gasses. © 2009 American Institute of Chemical Engineers Biotechnol. Prog., 2009