Urease-Mediated Reversible Calcium Carbonate Mineralization for Single Living Yeast Cell Nanoencapsulation

Modifying cells to achieve desired functions has attracted extensive attention in bioengineering and bio-manufacturing. Approaches based on cell-surface engineering have the potential to endow cells with multiple functions and also create a protective shell around them. However, such shells are generally irreversible and lack functionality, leading to various drawbacks associated with irreversible dynamics. This study describes a facile strategy for enzyme-catalyzed reversible CaCO₃ mineralization for single-living yeast cell nanoencapsulation. Urease is employed as an effective catalyst and covalently immobilized onto the yeast cell surface using poly(sodium acrylate) as the mediator. CaCO₃ mineralization proceeds via urease-catalyzed urea hydrolysis and coprecipitation with CaCl₂. Because urease covalently bonds to the yeast cell surface, reversible mineralization is achieved through EDTA-induced decomposition and urease-induced remineralization. In addition, the encapsulated urease endowed the engineered cell with catalytic sites for urea utilization, demonstrating the multifunctionality of the shell. This strategy realizes enzyme-catalyzed reversible mineralization of single living cells and demonstrates its potential in the construction of multifunctional shells, providing a nanoscale tool for structural modification to obtain single-cell factories for application in bioengineering and bio-manufacturing.