Rapid and Continuous Directed Evolution in <i>Vibrio natriegens</i> Utilizing an <i>In Vivo</i> Hypermutation System

Genetic diversification serves as the foundation for in vivo molecular evolution. The fusion of a cytidine deaminase with T7 RNA polymerase (MutaT7) enables efficient diversification of DNA sequences downstream of the T7 promoter in model microbial hosts E. coli and S. cerevisiae . Vibrio natriegens, currently the fastest-growing nonpathogenic bacterium with a doubling time half that of E. coli, emerged as a promising alternative chassis for synthetic biology. Here, we report the establishment of MutaT7 in V. natriegens (dubbed VnMutaT7), achieving rapid evolution of the model protein TEM-1 to confer high-level ceftazidime resistance in just 36 h. This work establishes the potential of V. natriegens as an accelerated platform for protein engineering.