Prospects in Mitigating Global Warming by Biomimetic Carbon Sequestration Using Recombinant Microbial Carbonic Anhydrases

Abstract

Carbon capture storage and utilization (CCSU) can be a probable and efficient solution for mitigating global warming. It refers to the conversion and storage of CO2 in stable and usable forms. Carbon sequestration using carbonic anhydrase (CA) has attracted much attention in the recent years. Due to high temperature and CO2 content in flue gas emitted from coal-based thermal plants, the enzyme for CO2 sequestration must have thermostability, tolerance to high CO2 and heavy metals, and alkalistability for mineralization. The extremophilic microbial CAs with these attributes would be useful in sequestering CO2. The production of large quantities of native carbonic anhydrase from wild microbial strains for carbon capture becomes costly because they possess low levels of CA. The cloning CA-encoding genes from extremophiles and their overexpression in heterologous hosts such as E. coli would bring down the cost of enzyme production. Further improvement in the desirable properties of CAs can be achieved through protein engineering approaches. In this chapter, an attempt has been made to review developments in the production of recombinant CAs, their characteristics and applicability in carbon sequestration. Other biotechnological applications of CAs are also briefly discussed.