Characterization of marine bacterial carbonic anhydrase and their CO₂ sequestration abilities based on a soil microcosm

Abstract

The novel technology of biological carbon sequestration using microbial enzymes have numerous advantages over conventional sequestration strategies. In the present study, extracellular carbonic anhydrase (CA) producing bacteria were isolated from water samples in the Arabian Sea, India. A potential isolate, Bacillus safensis isolate AS-75 was identified based on 16S rDNA sequence analysis. The culture conditions suitable for CA production were 32 °C incubation temperature with 4% NaCl and 10 mM Zn supplementation. Experimental optimization of culture conditions enhanced enzyme activity to 265 U mL⁻¹. CA specific gene was characterized and based on the analysis, the CA of B. safensis isolate AS-75 was a leucine (11.3%) with α-helices as the dominant component in its secondary structure. Based on soil microcosm studies, CA could sequester CO₂ by 95.4% ± 0.11% in sterilized soil with enzyme microcosm. Hence, the application of enzyme was found to be more effective in removing CO₂.

Keywords:

• Carbonic anhydrase
• CO₂ sequestration
• enzyme optimization
• kinetics
• microcosm

Acknowledgements

The authors are grateful to the Director, NIO, Goa and Scientist-in-charge, CSIR-NIO (RC), Kochi for their support and advice.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

NVK acknowledge the financial support of Science and Engineering Research; (SERB), Government of India through National Post-Doctoral fellowship [PDF/2016/000438]. This is NIO contribution number 6415.