Two-dimensional zirconium-based metal-organic frameworks as versatile scaffolds for whole-cell biocatalysis

Whole-cell catalysis enables the integration of multiple enzymatic functions within a single living system, but its broader application is often constrained by poor operational stability and limited mass transfer under non-physiological conditions. Material-assisted immobilization offers a route to enhance stability, yet conventional three-dimensional (3D) MOFs are poorly suited for whole-cell encapsulation due to rigid microporous architectures and harsh synthesis conditions. Here, we report a chemically engineered two-dimensional (2D) zirconium-based MOF, Zr-BTB, as a scaffold for whole-cell biocatalysts. Post-synthetic modification with sulfonic acid and octanoic acid groups tailors surface hydrophilicity and hydrophobicity, promoting stable interactions with microbial membranes and providing protection under thermal, solvent, and ultraviolet (UV) stress. Using Escherichia coli expressing Pasteurella multocida heparin synthase 2 (PmHS2) as a model system, Zr-BTB immobilization markedly improves catalytic stability and maintains substantial activity, whereas immobilization with conventional 3D zinc-based MOF ZIF-8 led to an almost complete loss of catalytic performance. Furthermore, the platform is generalizable across multiple enzymatic pathways, including Arbutin Synthase, Neisseria meningitidis β1-3-N-acetylglucosaminyltransferase (NmLgtA), and Nitroreductase B, demonstrating that 2D Zr-BTB is a versatile, chemically engineered exoskeleton for whole-cell biotransformations.