title: Biomineralization-based conversion of carbon dioxide to calcium carbonate using recombinant carbonic anhydrase.
abstract: Recently, as a mimic of the natural biomineralization process, the use of carbonic anhydrase (CA), which is an enzyme catalyzing fast reversible hydration of carbon dioxide to bicarbonate, has been suggested for biological conversion of CO(2) to valuable chemicals. While purified bovine CA (BCA) has been used in previous studies, its practical utilization in CO(2) conversion has been limited due to the expense of BCA preparation. In the present work, we investigated conversion of CO(2) into calcium carbonate as a target carbonate mineral by using a more economical, recombinant CA. To our knowledge, this is the first report of the usage of recombinant CA for biological CO(2) conversion. Recombinant α-type CA originating in Neisseria gonorrhoeae (NCA) was highly expressed as a soluble form in Escherichia coli. We found that purified recombinant NCA which showed comparable CO(2) hydration activity to commercial BCA significantly promoted formation of solid CaCO(3) through the acceleration of CO(2) hydration rate, which is naturally slow. In addition, the rate of calcite crystal formation was also accelerated using recombinant NCA. Moreover, non-purified crude recombinant NCA also showed relatively significant ability. Therefore, recombinant CA could be an effective, economical biocatalyst in practical CO(2) conversion system.
authors.affiliation: Department of Chemical Engineering, Pohang University of Science and Technology, Pohang 790-784, Republic of Korea.
authors.forename: Im Gyu
authors.initials: IG
authors.lastname: Kim
authors.forename: Byung Hoon
authors.initials: BH
authors.lastname: Jo
authors.forename: Dong Gyun
authors.initials: DG
authors.lastname: Kang
authors.forename: Chang Sup
authors.initials: CS
authors.lastname: Kim
authors.forename: Yoo Seong
authors.initials: YS
authors.lastname: Choi
authors.forename: Hyung Joon
authors.initials: HJ
authors.lastname: Cha
mesh_terms: D000818:Animals; D015153:Blotting, Western; D002119:Calcium Carbonate / Q000032:analysis / Q000378:metabolism*; D002245:Carbon Dioxide / Q000032:analysis / Q000378:metabolism*; D057965:Carbon Sequestration; D002256:Carbonic Anhydrases / Q000191:economics / Q000235:genetics / Q000378:metabolism*; D002417:Cattle; D003001:Cloning, Molecular; D004591:Electrophoresis, Polyacrylamide Gel; D004926:Escherichia coli / Q000201:enzymology / Q000235:genetics; D015964:Gene Expression Regulation, Bacterial; D015971:Gene Expression Regulation, Enzymologic; D007218:Industrial Microbiology / Q000191:economics / Q000379:methods*; D009344:Neisseria gonorrhoeae / Q000201:enzymology* / Q000235:genetics; D011994:Recombinant Proteins / Q000191:economics / Q000235:genetics / Q000378:metabolism; D014961:X-Ray Diffraction
chemical_list: D011994:Recombinant Proteins; D002245:Carbon Dioxide; D002256:Carbonic Anhydrases; D002119:Calcium Carbonate