Isolation and Characterization of Membrane Vesicles from Lactobacillus Species.

Throughout their life cycle, bacteria shed portions of their outermost membrane comprised of proteins, lipids, and a diversity of other biomolecules. These biological nanoparticles have been shown to have a range of highly diverse biological activities, including pathogenesis, community regulation, and cellular defense (among others). In recent publications, we have isolated and characterized membrane vesicles (MVs) from several species of Lactobacilli, microbes classified as commensals within the human gut microbiome ( Dean et al., 2019 and 2020). With increasing scientific understanding of host-microbe interactions, the gut-brain axis, and tailored probiotics for therapeutic or performance increasing applications, the protocols described herein will be useful to researchers developing new strategies for gut community engineering or the targeted delivery of bio-active molecules. Graphic abstract: Figure 1. Atomic force microscopic image of Lactobacillus casei ATCC 393 bacteria margins (white arrows) and membrane vesicles (black arrows).