Characterizing the Transport and Surface Affinity of Extracellular Vesicles Isolated from Yeast and Bacteria in Well-Characterized Porous Media

• Published in: Environmental science & technology Vol. 57; no. 35; pp. 13182 - 13192
• Main Authors: Rogers, Nicholas M. K., Hicks, Ethan, Kan, Christopher, Martin, Ethan, Gao, Lijia, Limso, Clariss, Hendren, Christine Ogilvie, Kuehn, Meta, Wiesner, Mark R.
• Format: Journal Article
• Language: English
• Published: Easton American Chemical Society 05.09.2023
• Subjects: Affinity; Bacteria; Deposition; Extracellular vesicles; Glass beads; Humic acids; Immunomodulation; Ionic strength; Ions; Membrane vesicles; Occurrence, Fate, and Transport of Aquatic and Terrestrial Contaminants; Porous media; Pseudomonas fluorescens; Saccharomyces cerevisiae; Surface charge; Surface chemistry; Vesicles; Yeast; Yeasts; extracellular membrane vesicle; colloid; fate; surface chemistry; transport model
• ISSN: 0013-936X; 1520-5851
• DOI: 10.1021/acs.est.3c03700

Extracellular vesicles (EVs) are membrane-bounded, nanosized particles, produced and secreted by all biological cell types. EVs are ubiquitous in the environment, operating in various roles including intercellular communication and plant immune modulation. Despite their ubiquity, the role of EV surface chemistry in determining transport has been minimally investigated. Using the zeta (ζ)-potential as a surrogate for surface charge, this work considers the deposition of EVs from the yeast, Saccharomyces cerevisiae, and two bacterial species, Staphylococcus aureus and Pseudomonas fluorescens, in well-characterized porous medium under various background conditions shown to influence the transport of other environmental colloidal particles: ionic strength and humic acid concentration. The affinity of S. cerevisiae EVs for the porous medium (glass beads) appeared to be sensitive to changes in ionic strength, as predicted by colloid stability (Derjaguin, Landau, Verwey, and Overbeek or DLVO) theory, and humic acid concentration, while P. fluorescens EVs deviated from DLVO predictions, suggesting that mechanisms other than charge stabilization may control the deposition of P. fluorescens. Calculations of attachment efficiency from these deposition studies were used to estimate EV transport using a clean-bed filtration model. Based on these calculations, EVs could be transported through such homogeneous porous media up to 15 m.