Lactobacillus acidophilus Membrane Vesicles as a Vehicle of Bacteriocin Delivery

Abstract

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 Lactobacillus acidophilus MVs to carry and deliver bacteriocin peptides to the opportunistic pathogen, Lactobacillus delbrueckii. We demonstrate that upon treatment with lactacin B-inducing peptide, the proteome of the secreted MVs is enriched in putative bacteriocins encoded by the lab operon. Further, we show that purified MVs inhibit growth and compromise membrane integrity in L. delbrueckii, which is confirmed by confocal microscopy imaging and spectrophotometry. These results show that L. acidophilus 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 L. acidophilus may be an interesting platform for effecting change in complex microbial communities or aiding in the development of new biomedical therapeutics.

The Impacts of Sortase A and the 4′-Phosphopantetheinyl Transferase Homolog Sfp on Streptococcus mutans Extracellular Membrane Vesicle Biogenesis

“…Bacteriocin Smu_1904c was found in EMVs, but not CMs, of the WT and its srtA and sfp mutant strains. This result is consistent with findings in Lactobacillus acidophilus in which membrane vesicles were identified as a delivery vehicle for bacteriocin (Dean et al, 2020). Also prevalent in S. mutans EMVs were glucosyl hydrolases, Gtfs, and Gbps, all of which are well established S. mutans virulence attributors that play a significant role in facilitating biofilm formation (Lemos et al, 2019).…”

Distribution of Select Cement Proteins in the Acorn Barnacle Amphibalanus amphitrite

“…For detailed LC and MS instrument settings and data processing protocols, see Supplementary File S1. Shotgun proteome profiling by LC-MS/MS was performed with a U3000 HPLC system coupled to an Orbitrap Fusion Lumos Tribrid mass spectrometer (Thermo Fisher Scientific, Waltham, MA, United States) as previously detailed (Dean et al, 2020). The Orbitrap acquired profile (or untargeted) measurements and targeted measurements ( Supplementary Table S1) for observed mass-to-charge (m/z) ratios in data dependent mode with dynamic exclusion enabled.…”

Strain heterogeneity, cooccurrence network, taxonomic composition and functional profile of the healthy ocular surface microbiome

“…A number of studies in the intestine and other microbiome sites have shown that cohabiting microorganisms within a microbiome maintain a stable state of competition and cooperation, such as competing with one another for or mutually utilizing resources, nutrition, and space [ 14 , 15 ]. The abundance of each member of the microbiome is constrained by the optimal ratio to maintain homeostasis [ 14 ].…”