Abstract
All Gram–negative and Gram–positive bacteria isolated to date secrete membrane–embedded nanoparticles called extracellular membrane vesicles (MVs) or outer membrane vesicles (OMVs). These vesicles play important roles in bacterial survival, such as infection to host cells and biofilm formation. MVs are used as a tool for inter– or intra–communication in these bacterial processes. Membrane vesicle production by bacteria is important for understanding bacterial survival strategies, and the development of vaccines, drug delivery, and heterologous protein production using them has attracted much attention. Shewanella vesiculosa HM13, a Gram–negative bacterium, was isolated from fish intestines as a promising host strain for the heterologous protein secretion system. This strain secretes a large number of EMVs that uniquely carry a single major cargo, namely P49. This review summarizes a unique feature of this non–model bacterium and the unique protein cargo loading mechanism.
