Immobilization of carbonic anhydrase enzyme purified from Bacillus subtilis VSG-4 and its application as CO(2) sequesterer.
The purification, immobilization, and characterization of carbonic anhydrase (CA) secreted by Bacillus subtilis VSG-4 isolated from tropical soil have been investigated in this work. Carbonic anhydrase was purified using ammonium sulfate precipitation, Sephadex-G-75 column chromatography, and DEAE-cellulose chromatography, achieving a 24.6-fold purification. The apparent molecular mass of purified CA obtained by SDS-PAGE was found to be 37 kD. The purified CA was entrapped within a chitosan-alginate polyelectrolyte complex (C-A PEC) hydrogel for potential use as an immobilized enzyme. The optimum pH and temperature for both free and immobilized enzymes were 8.2 and 37°C, respectively. The immobilized enzyme had a much higher storage stability than the free enzyme. Certain metal ions, namely, Co(2+), Cu(2+), and Fe(3+), increased the enzyme activity, whereas CA activity was inhibited by Pb(2+), Hg(2+), ethylenediamine tetraacetic acid (EDTA), 5,5'-dithiobis-(2-nitrobenzoic acid (DTNB), and acetazolamide. Free and immobilized CAs were tested further for the targeted application of the carbonation reaction to convert CO(2) to CaCO(3). The maximum CO(2) sequestration potential was achieved with immobilized CA (480 mg CaCO(3)/mg protein). These properties suggest that immobilized VSG-4 carbonic anhydrase has the potential to be used for biomimetic CO(2) sequestration.
Department of Biotechnology, Periyar Maniammai University, Thanjavur, Tamil Nadu, India.
M
M
Oviya
Sib Sankar
SS
Giri
V
V
Sukumaran
P
P
Natarajan
D000086:Acetazolamide / Q000737:chemistry; D000464:Alginates / Q000737:chemistry; D001412:Bacillus subtilis / Q000737:chemistry* / Q000201:enzymology / Q000302:isolation & purification; D002245:Carbon Dioxide / Q000737:chemistry / Q000302:isolation & purification*; D002257:Carbonic Anhydrase Inhibitors / Q000737:chemistry; D002256:Carbonic Anhydrases / Q000737:chemistry*; D048271:Chitosan / Q000737:chemistry; D002850:Chromatography, Gel; D002852:Chromatography, Ion Exchange; D004228:Dithionitrobenzoic Acid / Q000737:chemistry; D004492:Edetic Acid / Q000737:chemistry; D004591:Electrophoresis, Polyacrylamide Gel; D004800:Enzymes, Immobilized / Q000037:antagonists & inhibitors / Q000737:chemistry; D020723:Glucuronic Acid / Q000737:chemistry; D006603:Hexuronic Acids / Q000737:chemistry; D020100:Hydrogels; D006863:Hydrogen-Ion Concentration; D019216:Metals, Heavy / Q000737:chemistry; D012988:Soil Microbiology; D013696:Temperature
D000464:Alginates; D002257:Carbonic Anhydrase Inhibitors; D004800:Enzymes, Immobilized; D006603:Hexuronic Acids; D020100:Hydrogels; D019216:Metals, Heavy; D002245:Carbon Dioxide; D020723:Glucuronic Acid; D048271:Chitosan; D004228:Dithionitrobenzoic Acid; D004492:Edetic Acid; D002256:Carbonic Anhydrases; D000086:Acetazolamide