Abstract
Outer membrane vesicles (OMVs) represent a unique sub-cellular compartment of bacteria that may act as a scaffold for various extracellular activities, including intercellular signaling. Myxococcus xanthus (M. xanthus) is a predatory bacterium that engages in cell-cell behaviors such as fruiting body formation and contact dependent lysis of other microbes. The OMVs of M. xanthus have been shown to have an elaborate architecture of chains and tubes that can connect cells within a biofilm. These higher order OMV structures have been shown to contain proteins exchanged for community behaviors and small molecules that have antibiotic activities, and may help facilitate directed exchange. M. xanthus OMVs allow material transfer between neighboring cells for motility and predation.
Keywords: EPS, Biofilm, Cell fractioning, Proteomics, Extracellular
Materials and Reagents
Equipment
Software
Procedure
Notes
Other EM analysis methods [SEM, resin-embedded sections TEM, cryo-EM of frozen-hydrated vesicle samples (Remis et al., 2014)] are also feasible for this assessment, but negative stain TEM is the simplest technique that provides this information. Light microscopy alone, due to its limited resolution, typically fails to provide accurate assessments of vesicle purifications. Figure 1. TEM image of M. xanthus OMVs (from Remis et al., 2014) showing isolated OMVs as well as OMV chains
Recipes
Acknowledgments
This protocol was adapted from previous work (Berleman et al., 2014; Palsdottir et al., 2009; Remis et al., 2014). This work was Supported by Lab directed research development funds from the Office of Biological and Environmental Research of the US Department of Energy under contract number DE-AC02-05CH11231 (to Manfred Auer) and the US Department of Energy VFP program (to James E. Berleman).
References
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