Robust Biocatalysts Displayed on Crystalline Protein‐Layered Cells for Efficient and Sustainable Hydration of Carbon Dioxide

Mineral carbonation is the most effective carbon capture technique, but carbon dioxide (CO 2 ) conversion is limited by the slow hydration rate of CO 2 (<10 −1  s −1 ). A biological solution exists: carbonic anhydrase (CA) efficiently hydrates CO 2 at a turnover rate of ≈10 6  s −1 under ambient conditions, making it an extremely attractive candidate for industrial post‐combustion CO 2 capture. However, high cost and poor long‐term stability impose a technical barrier to its practical uses. Here, a genetically engineered Corynebacterium glutamicum ( C. glutamicum ) is introduced as a robust cell display platform for the in situ stabilization and low‐cost production of CA. The enzyme is displayed in the mycolic layer with porin B as an anchoring protein with (GGGGS) 2 as a spacer. The cell‐displayed CA exhibits no significant inactivation of the CO 2 hydration activity for at least one month at 37 °C. Its denaturation rate constant at 50 °C (0.07) is an order of magnitude lower than that of free CA (0.52–0.54). This study demonstrates that a structurally robust cell template allows the effective stabilization of CA, suggesting the C. glutamicum ‐based cell display as a promising technique to achieve highly efficient, sustainable, and low‐cost CO 2 capture for industrial applications.