Bacterial membrane injuries induced by lactacin F and nisin

• M. Dalmau ^[1] ; Elke Maier ^[2] ; Natalia Mulet ^[1] ; Miguel Viñas ^[1] ; Roland Benz ^[2]
  1. [1] Universitat de Barcelona

     Universitat de Barcelona

     Barcelona, España

     
  2. [2] Lehrstuhlfür Biotechnologie, Theodor-Boveri-Institut (Biozentrum) der Universität Würzburg, Am Hubland, Würzburg, Germany
• Localización: International microbiology: official journal of the Spanish Society for Microbiology, ISSN 1139-6709, Vol. 5, Nº. 2, 2002, págs. 73-80
• Idioma: inglés
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• Resumen

  • The combined action of nisin and lactacin F, two bacteriocins produced by lactic acid bacteria, is additive. In this report, the basis of this effect is examined. Channels formed by lactacin F were studied by experiments using planar lipid bilayers, and bactericidal effects were analyzed by flow cytometry. Lactacin F produced pores with a conductance of 1 ns in black lipid bilayers in 1 mM KClat 10 mV at 20°C. Pore formation was strongly dependent on voltage. Although lactacin F formed pores at very low potential (10 mV), the dependence was exponentialabov e 40 mV. The injuries induced by nisin and lactacin F in the membranes of Lactobacillus helveticus produced different flow cytometric profiles. Probably, when both bacteriocins are present, each acts separately; their cooperation may be due to an increase in the number of single membrane injuries.