title: Immobilization and characterization of carbonic anhydrase purified from E. coli MO1 and its influence on CO₂ sequestration.
abstract: The present investigation entails the immobilisation and characterisation of Escherichia coli MO1-derived carbonic anhydrase (CA) and its influence on the transformation of CO₂ to CaCO₃. CA was purified from MO1 using a combination of Sephadex G-75 and DEAE cellulose column chromatography, resulting in 4.64-fold purification. The purified CA was immobilised in chitosan-alginate polyelectrolyte complex (C-A PEC) with an immobilisation potential of 94.5 %. Both the immobilised and free forms of the enzyme were most active and stable at pH 8.2 and at 37 °C. The K(m) and V(max) of the immobilised enzyme were found to be 19.12 mM and 416.66 μmol min⁻¹ mg⁻¹, respectively; whereas, the K(m) and V(max) of free enzyme were 18.26 mM and 434.78 μmol min⁻¹ mg⁻¹, respectively. The presence of metal ions such as Cu²⁺, Fe²⁺, and Mg²⁺ stimulated the enzyme activity. Immobilised CA showed higher storage stability and maintained its catalytic efficiency after repeated operational cycles. Furthermore, both forms of the enzyme were tested for targeted application of the carbonation reaction to convert CO₂ to CaCO₃. The amounts of CaCO₃ precipitated over free and immobilised CA were 267 and 253 mg/mg of enzyme, respectively. The results of this study show that immobilised CA in chitosan-alginate beads can be useful for CO₂ sequestration by the biomimetic route.
authors.affiliation: Department of Biotechnology, Periyar Maniammai University, Thanjavur, 613403, Tamil Nadu, India.
authors.forename: M
authors.initials: M
authors.lastname: Oviya
authors.forename: V
authors.initials: V
authors.lastname: Sukumaran
authors.forename: Sib Sankar
authors.initials: SS
authors.lastname: Giri
mesh_terms: D000464:Alginates / Q000378:metabolism; D002119:Calcium Carbonate / Q000378:metabolism*; D002245:Carbon Dioxide / Q000378:metabolism*; D002256:Carbonic Anhydrases / Q000737:chemistry / Q000302:isolation & purification* / Q000378:metabolism*; D048271:Chitosan / Q000378:metabolism; D002850:Chromatography, Gel; D002852:Chromatography, Ion Exchange; D020536:Enzyme Activators / Q000032:analysis; D004795:Enzyme Stability; D004800:Enzymes, Immobilized / Q000737:chemistry / Q000378:metabolism*; D004926:Escherichia coli / Q000201:enzymology*; D020723:Glucuronic Acid / Q000378:metabolism; D006603:Hexuronic Acids / Q000378:metabolism; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D008863:Microspheres; D013696:Temperature
chemical_list: D000464:Alginates; D020536:Enzyme Activators; D004800:Enzymes, Immobilized; D006603:Hexuronic Acids; D002245:Carbon Dioxide; D020723:Glucuronic Acid; D048271:Chitosan; D002256:Carbonic Anhydrases; D002119:Calcium Carbonate
references.citation: Int J Biol Macromol. 2005 Nov 15;37(3):148-53; author reply 156-60
references.pmid: 16274740
references.citation: FEMS Microbiol Rev. 2000 Oct;24(4):335-66
references.pmid: 10978542
references.citation: J Appl Microbiol. 2000 Dec;89(6):1048-58
references.pmid: 11123478
references.citation: J Physiol Pharmacol. 2006 Nov;57 Suppl 8:107-23
references.pmid: 17242477
references.citation: Enzyme Microb Technol. 2011 Apr 7;48(4-5):416-26
references.pmid: 22112959
references.citation: Prep Biochem Biotechnol. 2012;42(5):462-75
references.pmid: 22897768
references.citation: Proc Natl Acad Sci U S A. 2007 Jun 12;104(24):10288-93
references.pmid: 17519334
references.citation: J Biol Chem. 1948 Oct;176(1):147-54
references.pmid: 18886152
references.citation: Nature. 1970 Aug 15;227(5259):680-5
references.pmid: 5432063
references.citation: EMBO J. 1998 Aug 10;17(5):1208-16
references.pmid: 9482718
references.citation: J Biol Chem. 1994 Oct 7;269(40):24742-6
references.pmid: 7929150
references.citation: J Biol Chem. 2004 Feb 20;279(8):6683-7
references.pmid: 14662760
references.citation: J Biol Chem. 1951 Nov;193(1):265-75
references.pmid: 14907713