Response of Salmonella choleraesuis LT2 spheroplasts and permeabilized cells to the bacteriocin AS-48.
The bacteriocin AS-48 was not active against intact cells of Salmonella choleraesuis LT2 at neutral pH, but it was very effective on spheroplasts, suggesting that the outer membrane (OM) acts as a protective barrier. Cells sublethally injured by heat or treated with OM-permeabilizing agents (i.e., EDTA and Tris) became sensitive to AS-48. The combination of two or more treatments decreased the amount of AS-48 required for cell killing. The activity of AS-48 against heat-injured cells did not change significantly in the pH range of 4.0 to 8.0. AS-48 showed bactericidal activity against intact cells of Salmonella at pH 4.0. The potency of AS-48 increased greatly when the bacteriocin was dissolved at pH 9.0.
Abriouel
H
H
Dpto. Microbiología, Facultad de Ciencias, Universidad de Granada, Fuentenueva s/n, E-18071-Granada, Spain.
Valdivia
E
E
Gálvez
A
A
Maqueda
M
M
D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D001425:Bacterial Outer Membrane Proteins / Q000502:physiology; D001426:Bacterial Proteins; D002463:Cell Membrane Permeability; D004492:Edetic Acid / Q000494:pharmacology; D005516:Food Microbiology; D005519:Food Preservation / Q000379:methods; D006358:Hot Temperature; D006863:Hydrogen-Ion Concentration; D010455:Peptides; D012475:Salmonella / Q000187:drug effects*; D013104:Spheroplasts / Q000187:drug effects; D014325:Tromethamine / Q000494:pharmacology
D000900:Anti-Bacterial Agents; D001425:Bacterial Outer Membrane Proteins; D001426:Bacterial Proteins; D010455:Peptides; D014325:Tromethamine; C051034:BacA protein, Enterococcus faecalis; D004492:Edetic Acid