When cultured in minimal growth medium, the B38 strain of Bacillus subtilis did not exhibit any antibacterial activity against methicillin-resistant Staphylococcus aureus (MRSA) clinical isolate. Coculturing B38 strain with viable MRSA cells weakly increased antibacterial activity production (20 AU/ml). Addition of dead MRSA cells in a B38 culture, increased by 8-fold the B. subtilis strain antibacterial activity reaching 160 AU/ml against MRSA strain. This antibacterial activity recovered from cell-free supernatants was stimulated by an autoinducing compound which is sensitive to the action of proteinase K suggesting a proteinaceous nature. This compound was heat-stable till 80 A degrees C and showed a molecular mass around 20 kDa as determined by SDS-PAGE. These results suggest that the production of antibacterial compounds by B38 strain is dependent on the amount of the autoinducing compound.
Triggering of the Antibacterial Activity of Bacillus subtilis B38 Strain against Methicillin-Resistant Staphylococcus aureus / Olfa, Tabbene; Ines, Karkouch; Imen Ben, Slimene; Najib, Elfeddy; Pascal, Cosette; Mangoni, Maria Luisa; Thierry, Jouenne; Ferid, Limam. - In: APPLIED BIOCHEMISTRY AND BIOTECHNOLOGY. - ISSN 0273-2289. - STAMPA. - 164:1(2011), pp. 34-44. [10.1007/s12010-010-9112-z]
Triggering of the Antibacterial Activity of Bacillus subtilis B38 Strain against Methicillin-Resistant Staphylococcus aureus
MANGONI, Maria Luisa;
2011
Abstract
When cultured in minimal growth medium, the B38 strain of Bacillus subtilis did not exhibit any antibacterial activity against methicillin-resistant Staphylococcus aureus (MRSA) clinical isolate. Coculturing B38 strain with viable MRSA cells weakly increased antibacterial activity production (20 AU/ml). Addition of dead MRSA cells in a B38 culture, increased by 8-fold the B. subtilis strain antibacterial activity reaching 160 AU/ml against MRSA strain. This antibacterial activity recovered from cell-free supernatants was stimulated by an autoinducing compound which is sensitive to the action of proteinase K suggesting a proteinaceous nature. This compound was heat-stable till 80 A degrees C and showed a molecular mass around 20 kDa as determined by SDS-PAGE. These results suggest that the production of antibacterial compounds by B38 strain is dependent on the amount of the autoinducing compound.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.