Ribosome-engineered <i>Lacticaseibacillus rhamnosus</i> GG with enhanced adhesion and immune activation via surface moonlighting proteins

Ribosome engineering, a microbial breeding strategy that induces spontaneous mutations via treatment with antibiotics, has led to novel functionalities in <i>Lacticaseibacillus rhamnosus</i> GG. A study of streptomycin-resistant <i>rpsL</i> mutants identified the K56N mutation as a key driver of enhanced protein display on the bacterial surface. This mutation promoted strong adhesion to intestinal cells and immunostimulatory effects in macrophages. The mutation also triggered transcriptomic shifts and morphologic changes, highlighting the broad range of bacterial modifications.