A branching cell-fate decision in biofilm dispersal enables long-term surface persistence

Biofilms are the most ancient multicellular communities on Earth, representing a primitive developmental system that protects microbes from threats. Biofilm dispersal, whereby bacteria exit biofilms, is critical for the spread of pathogens to new infection sites. Here, using Vibrio cholerae, we show that dispersal events are accompanied by a branching cell-fate decision. While ~90% of cells disperse, a viable subpopulation remains within a residual matrix. This post-dispersal biofilm community (PDBC) is established by the matrix protein RbmA and adopts a specialized anabolic program that enhances tolerance to antibiotics and bacteriophages. Our findings reveal that PDBCs act as a resilient "seed-bank" capable of rapidly re-populating the niche without requiring de novo matrix biosynthesis, providing a mechanistic basis for the recurrence and spread of chronic infections.