Isolation and Visualization Fusobacterium nucleatum Microcompartments.

In Fusobacterium nucleatum, bacterial microcompartments (BMCs) are polyhedral organelles that encapsulate the catabolism of ethanolamine (EA), creating a specialized environment that protects the rest of the cell from toxic metabolic byproducts. In this chapter, we present a protocol for the isolation and visualization of F. nucleatum BMCs with transmission electron microscopy (TEM), cryogenic electron microscopy (cryoEM), and cryogenic electron tomography (cryoET). The protocol includes anaerobic cultivation of F. nucleatum, a strategy for BMC purification, sample preparation and image acquisition for TEM, cryoEM, and cryoET, followed by 3D reconstruction and visualization. These approaches are adaptable to BMCs from other bacterial species, offering a robust framework for structural and functional studies of diverse BMC systems.