Mode of action of thuricin S, a new class IId bacteriocin from Bacillus thuringiensis.
Different methods were used to elucidate the mode of action of thuricin S, a new class IId bacteriocin produced by Bacillus thuringiensis subsp. entomocidus HD198. According to cell viability tests, thuricin S was shown to exert a bactericidal effect on the sensitive cells of Bacillus thuringiensis subsp. darmastadiensis 10T. The use of the fluorescent probe 3,3'-dipropylthiadicarbocyanine iodide as an indicator proved that thuricin S interacts with the cytoplasmic membrane to dissipate the transmembrane potential. It was also demonstrated that thuricin S acts as a pore-forming bacteriocin, since it allows the nonpermeable stain propidium iodide to enter the cells. The loss of membrane integrity and the morphological changes in sensitive cells were visualized by scanning electron microscopy.
UMR- Littoral environnement et sociétés, UFR Sciences, Université de La Rochelle - CNRS, France. chehimisonia@yahoo.fr
Sonia
S
Chehimi
Anne-Marie
AM
Pons
Sophie
S
Sablé
Mohamed-Rabeh
MR
Hajlaoui
Férid
F
Limam
D000900:Anti-Bacterial Agents / Q000378:metabolism / Q000494:pharmacology*; D001413:Bacillus thuringiensis / Q000187:drug effects / Q000378:metabolism* / Q000648:ultrastructure; D001430:Bacteriocins / Q000378:metabolism / Q000494:pharmacology*; D002462:Cell Membrane / Q000187:drug effects; D005456:Fluorescent Dyes / Q000378:metabolism; D008564:Membrane Potentials / Q000187:drug effects; D050296:Microbial Viability / Q000187:drug effects; D008855:Microscopy, Electron, Scanning; D013194:Staining and Labeling / Q000379:methods
D000900:Anti-Bacterial Agents; D001430:Bacteriocins; D005456:Fluorescent Dyes; C059740:thuricin