Expression, reconstruction and characterization of codon-optimized carbonic anhydrase from Hahella chejuensis for CO2 sequestration application

Abstract

The high production of functional carbonic anhydrase (CA) is required for practical CO2 sequestration application mediated by CA. Here, the synthetic gene based on Escherichia coli codon usage of new alpha-type CA (HC-aCA) of Hahella chejuensis, a Korea marine microorganism, was highly expressed in E. coli. We obtained a high yield of functional HC-aCA by denaturing/refolding process and incorporating zinc ion into its active site. The refolded HC-aCA displayed a half-deactivation temperature of 60 A degrees C with maximal activity at 50 A degrees C, and had high pH stability in alkali condition with maximal activity at pH 10.0. The esterase activity of HC-aCA almost doubled at high salt concentration ranging from 0.67 to 2.0 M NaCl. HC-aCA catalyzed the conversion of CO2 to CaCO3 as calcites form in the presence of Ca2+. The refolded HC-aCA could be a promising candidate for the development of efficient CA-based CO2 sequestration processes.