CARBONIC ANHYDRASE AS AN INDUSTRIAL BIOCATALYST FOR CCUS

Carbonic anhydrase (CA) has been proposed as an industrial biocatalyst since the last century.1 Consolidated technologies for recombinant enzyme production and immobilization disclosed CA applications in continuous flow bioreactors opening up new opportunities for carbon capture utilization and storage (CCUS) as well as carbon removal processes.2,3 As a first successful process, the conventional acid gas absorption for CO2 post-combustion capture was rethought by replacing the amine-based solvents with CA-supplemented solutions3 (Figure 1). The present contribution provides a survey of the recent advancements in immobilization techniques specifically developed and applied to thermostable CAs isolated from extremophiles and aimed at the development of heterogeneous biocatalysts for CCUS. Covalent attachment on fine granular solids and supports with novel geometries, immobilization as cross-linked enzyme aggregates as well as in vivo immobilization methods will be discussed. Perspectives about the combination of enzymatic reactive CO2 absorption and biological/biocatalytic CO2 fixation pathways will be also addressed.