title: Evaluation of enhanced thermostability and operational stability of carbonic anhydrase from Micrococcus species.
abstract: Carbonic anhydrase (CA) was purified from Micrococcus lylae and Micrococcus luteus with 49.90 and 53.8 % yield, respectively, isolated from calcium carbonate kilns. CA from M. lylae retained 80 % stability in the pH and temperature range of 6.0-8.0 and 35-45 °C, respectively. However, CA from M. luteus was stable in the pH and temperature range of 7.5-10.0 and 35-55 °C, respectively. Cross-linked enzyme aggregates (CLEAs) raised the transition temperature of M. lylae and M. luteus CA up to 67.5 and 74.0 °C, while the operational stability (T(1/20) of CA at 55 °C was calculated to be 7.7 and 12.0 h, respectively. CA from both the strains was found to be monomeric in nature with subunit molecular weight and molecular mass of 29 kDa. Ethoxozolamide was identified as the most potent inhibitor based on both IC(50) values and inhibitory constant measurement (K(i)). The K(m) and V(max) for M. lylae CA (2.31 mM; 769.23 μmol/mg/min) and M. luteus CA (2.0 mM; 1,000 μmol/mg/min) were calculated from Lineweaver-Burk plots in terms of esterase activity. Enhanced thermostability of CLEAs alleviates its role in operational stability for application at an on-site scrubber. The characteristic profile of purified CA from Micrococcus spp. advocates its effective application in biomimetic CO(2) sequestration.
authors.affiliation: Bacteriology Laboratory, Department of P.G Studies and Research in Biological Science, Rani Durgavati University, Pachpedi, Jabalpur 482001, Madhya Pradesh, India.
authors.forename: Abhishek
authors.initials: A
authors.lastname: Bhattacharya
authors.forename: Ankita
authors.initials: A
authors.lastname: Shrivastava
authors.forename: Anjana
authors.initials: A
authors.lastname: Sharma
mesh_terms: D000086:Acetazolamide / Q000737:chemistry; D001426:Bacterial Proteins / Q000737:chemistry* / Q000302:isolation & purification; D002104:Cadmium / Q000737:chemistry; D002119:Calcium Carbonate / Q000737:chemistry; D002245:Carbon Dioxide / Q000737:chemistry; D002257:Carbonic Anhydrase Inhibitors / Q000737:chemistry; D002256:Carbonic Anhydrases / Q000737:chemistry / Q000302:isolation & purification*; D004789:Enzyme Activation; D004795:Enzyme Stability; D005016:Ethoxzolamide / Q000737:chemistry; D006863:Hydrogen-Ion Concentration; D016982:Micrococcus luteus / Q000201:enzymology*; D008970:Molecular Weight; D013696:Temperature; D015032:Zinc / Q000737:chemistry
chemical_list: D001426:Bacterial Proteins; D002257:Carbonic Anhydrase Inhibitors; D002104:Cadmium; D002245:Carbon Dioxide; D002256:Carbonic Anhydrases; D002119:Calcium Carbonate; D015032:Zinc; D000086:Acetazolamide; D005016:Ethoxzolamide