###### Abstract
The CA bioccmentation pathway adopted in this study is proposed as an innovative, eco-friendly, sustainable soil stabilisation method that can consume CO\({}_{2}\) from the atmosphere or use captured CO\({}_{2}\) to precipitate CaCO\({}_{3}\), which binds together (i.e., bioccments) soil particles. In this multi-step chemical process, CA catalyses the precipitation of calcite. The aqueous CO\({}_{2}\) (aq) formed (Equation (1)) reacts with water to form H\({}_{2}\)CO\({}_{3}\) (Equation (2)). The absorption of CO\({}_{2}\) in an aqueous medium entails the conversion of CO\({}_{2}\) (aqueous) to HCO\({}_{3}\) (Equation (3)). CA enzyme can substantially increase the rate of CO\({}_{2}\) mineralization by CA-catalysed hydration of CO\({}_{2}\) to HCO\({}_{3}\). This CO\({}_{2}\) -derived HCO\({}_{3}\) can be mineralized to metal carbonates that can be stored as CO\({}_{2}\) minerals or used in value-added chemicals and other products/materials (adhesives, sealants, food additives, pharmaceuticals, paints, coatings, paper, cement and construction materials [26]). \[\text{CO}_{2}\;\text{(g)}\leftrightarrow\text{CO}_{2}\;\text{(aq)} \tag{1}\]  
\[\text{CO}_{2}\;\text{(aq)}+\text{H}_{2}\text{O}\;\text{(}l)\leftrightarrow \text{H}_{2}\text{CO}_{3}\;\text{(aq)} \tag{2}\]  
To form a bioccent via biomineral precipitates, the metal ion, e.g., Ca\({}^{2+}\), reacts with CO\({}_{3}\)\({}^{2-}\) (Equation (5)), forming calcium carbonate, where the CA enzyme provides nucleation sites. \[\text{H}_{2}\text{CO}_{3}\text{(aq)}\leftrightarrow\text{H}^{+}+\text{HCO}_{3 }\text{${}^{-}$ (aq)} \tag{3}\]  
\[\text{HCO}_{3}\text{${}^{-}$}\leftrightarrow\text{H}^{+}+\text{CO}_{3}\text{${} ^{2-}$} \tag{4}\]  
\[\text{Ca}^{2+}+\text{CO}_{3}\text{${}^{2-}$}\leftrightarrow\text{CaCO}_{3}\; \text{(s)}\downarrow \tag{5}\]Due to the simplicity of the process, CA-mediated mineralization has become one of the most popular ways of CO\({}_{2}\) conversion and utilization. There are many examples in the literature, demonstrating that stabilized and immobilized CA drastically enhances CO\({}_{2}\) mineralization and retains most of its CO\({}_{2}\) mineralization capacity after many cycles of CaCO\({}_{3}\) mineralization for faster and more efficient CO\({}_{2}\) conversion and utilization (see, e.g., [26; 27]). Thus, a major industrial application of hybrid delivery systems is for carbon capture and storage (CCS) and carbon conversion and utilisation (CCU) technologies, where a basic requirement for the success of the processes is the adequate transfer of CO\({}_{2}\) from the gas phase to the aqueous phase. This critical requirement can be addressed by the use of the CA enzyme, whose active site contains hydroxide-bound Zn\({}^{2+}\) for catalysis of the interconversion between CO\({}_{2}\) and bicarbonate. However, a major challenge for the industrial implementation of CA is the poor stability of CA at high temperatures, in alkaline pH, or in the presence of high salt concentrations. Thus, producing robust CAs is essential; CA immobilization in hybrid nano-carriers is one way of addressing this challenge, while also enabling the easier recovery and reuse of enzymes, lowering the cost of CA per ton of captured/utilized CO\({}_{2}\). Furthermore, immobilization and stabilization of CA in nanostructured materials, allows CA to be placed together closely with other CO\({}_{2}\)-converting enzymes; this way CO\({}_{2}\) captured by CA can be transferred to other enzymes in order to improve the kinetics of CO\({}_{2}\) conversion. CA immobilization and stabilization in nanostructured materials also allows for the combination of immobilized CA with CO\({}_{2}\)-converting microorganisms. Overall, the immobilization of CA with nanostructured carriers gives promise for the development of highly stable and reusable CA for the faster and more efficient CO\({}_{2}\) conversion and utilization [28].