Targeted gene editing of bacterial cellulose biosynthesis-related genes enables programmable mechanical properties of bacterial cellulose

Bacterial cellulose (BC) is a sustainable biomaterial with excellent mechanical properties and broad application potential. Controlling BC structure and properties is important for its expanding applications and advancing industrial translation. Here, we establish a high-efficiency, seamless genome-editing system for Komagataeibacter xylinus based on mutant pheS gene and apply it to systematically evaluate the roles of bacterial cellulose synthesis (bcs) operon genes in BC production and properties. We found deletion of bcsCⅡ gene markedly enhances BC mechanical properties in K. xylinus P1: tensile strength and Young’s modulus reach 3.56-fold and 2.36-fold improvement, respectively. Multiscale structural analyses indicate that the enhancements arise from more uniform nanofibril assembly and a denser hierarchical network of BC. We further demonstrate that co-culture strategy or inducible expression of bcsCⅡ enable programmable control of BC mechanical properties. Collectively, this work provides an efficient genetic toolkit for K. xylinus, systematically reveals functional roles of bcs operon genes in BC assembly, and offers a rational route to engineer programmable high-performance BC materials.