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Enterocin P selectively dissipates the membrane potential of Enterococcus faecium T136
1Departmento de Nutrición y Bromatología III, Facultad de Veterinaria, Universidad Complutense, 28040 Madrid, Spain.
Abstract:
Enterocin P is a pediocin-like, broad-spectrum bacteriocin which displays a strong inhibitory activity against Listeria monocytogenes. The bacteriocin was purified from the culture supernatant of Enterococcus faecium P13, and its molecular mechanism of action against the sensitive strain E. faecium T136 was evaluated. Although enterocin P caused significant reduction of the membrane potential (DeltaPsi) and the intracellular ATP pool of the indicator organism, the pH gradient (DeltapH) component of the proton motive force (Deltap) was not dissipated. By contrast, enterocin P caused carboxyfluorescein efflux from E. faecium T136-derived liposomes.
Insights
Enterocin P, a bacteriocin from Enterococcus faecium, effectively inhibits Listeria monocytogenes. It disrupts bacterial membrane potential and ATP levels, but not the pH gradient, causing molecule efflux.
Area of Science:
- Microbiology
- Bacteriocin research
- Food safety
Background:
- Enterocin P is a broad-spectrum bacteriocin with potent activity against Listeria monocytogenes.
- Bacteriocins are antimicrobial peptides with potential applications in food preservation and pathogen control.
Purpose of the Study:
- To investigate the molecular mechanism of action of Enterocin P against the sensitive strain Enterococcus faecium T136.
- To elucidate how Enterocin P affects the membrane potential, intracellular ATP, and proton motive force of target bacteria.
Main Methods:
- Purification of Enterocin P from Enterococcus faecium P13 culture supernatant.
- Evaluation of Enterocin P's effect on membrane potential (DeltaPsi), intracellular ATP pool, and pH gradient (DeltapH).
- Assay of carboxyfluorescein efflux from Enterococcus faecium T136-derived liposomes.
Main Results:
- Enterocin P significantly reduced the membrane potential (DeltaPsi) and intracellular ATP pool in E. faecium T136.
- The pH gradient (DeltapH), a component of proton motive force (Deltap), was not dissipated by Enterocin P.
- Enterocin P induced carboxyfluorescein efflux from liposomes, indicating membrane permeabilization.
Conclusions:
- Enterocin P targets bacterial membranes, leading to dissipation of membrane potential and ATP depletion.
- The bacteriocin's mechanism involves pore formation or disruption of membrane integrity, rather than solely altering the pH gradient.
- Enterocin P shows promise as a natural antimicrobial agent for controlling foodborne pathogens like Listeria monocytogenes.