AUTHOR=Dean Scott N. , Rimmer Mary Ashley , Turner Kendrick B. , Phillips Daniel A. , Caruana Julie C. , Hervey William Judson , Leary Dagmar H. , Walper Scott A. 

TITLE=Lactobacillus acidophilus Membrane Vesicles as a Vehicle of Bacteriocin Delivery

JOURNAL=Frontiers in Microbiology

VOLUME=11

YEAR=2020

URL=https://www.frontiersin.org/journals/microbiology/articles/10.3389/fmicb.2020.00710

DOI=10.3389/fmicb.2020.00710

ISSN=1664-302X

ABSTRACT=<p>Recent reports have shown that Gram-positive bacteria actively secrete spherical nanometer-sized proteoliposome membrane vesicles (MVs) into their surroundings. Though MVs are implicated in a broad range of biological functions, few studies have been conducted to examine their potential as delivery vehicles of antimicrobials. Here, we investigate the natural ability of <italic>Lactobacillus acidophilus</italic> MVs to carry and deliver bacteriocin peptides to the opportunistic pathogen, <italic>Lactobacillus delbrueckii</italic>. We demonstrate that upon treatment with lactacin B-inducing peptide, the proteome of the secreted MVs is enriched in putative bacteriocins encoded by the <italic>lab</italic> operon. Further, we show that purified MVs inhibit growth and compromise membrane integrity in <italic>L. delbrueckii</italic>, which is confirmed by confocal microscopy imaging and spectrophotometry. These results show that <italic>L. acidophilus</italic> MVs serve as conduits for antimicrobials to competing cells in the environment, suggesting a potential role for MVs in complex communities such as the gut microbiome. With the potential for controlling their payload through microbial engineering, MVs produced by <italic>L. acidophilus</italic> may be an interesting platform for effecting change in complex microbial communities or aiding in the development of new biomedical therapeutics.</p>