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  • Anti-Escherichia coli O157:H7 properties of purple prairie clover and sainfoin condensed tannins.

Anti-Escherichia coli O157:H7 properties of purple prairie clover and sainfoin condensed tannins.

Molecules (Basel, Switzerland) (2013-02-12)
Xiu-Li Liu, Yong-Qing Hao, Long Jin, Zhong-Jun Xu, Tim A McAllister, Yuxi Wang
ZUSAMMENFASSUNG

Condensed tannins (CT) from purple prairie clover (PPC; Dalea purpurea Vent.) and sainfoin (SF; Onobrychis viciifolia) were assessed for anti-Escherichia coli activity by comparing their ability to react with proteins and liposome, cause cell aggregation, and alter outer membrane (OM) morphology and permeability. The PPC CT had greater (P < 0.01) protein-precipitating capacity than SF CT using either bovine serum albumin or ribulose 1,5-disphosphate carboxylase as model proteins. Minimum inhibitory concentration of PPC CT for two strains of E. coli and five strains of E. coli O157:H7 was four to six times lower than that of SF CT. E. coli exposed to 10 µg/mL of both CT had higher (P < 0.05) OM permeability than controls and was greater (P < 0.05) for PPC than for SF CT. Addition of both CT at 50 and 200 µg/mL caused cell aggregation which was more evident (P < 0.05) for PPC than for SF CT. Transmission electron microscopy showed electron dense material on the cell surface when cells were exposed to 50 µg/mL of PPC CT. The greater anti-E. coli activity of PPC than SF CT was due to its enhanced ability to precipitate protein that increased OM permeability and promoted cell aggregation.

MATERIALIEN
Produktnummer
Marke
Produktbeschreibung

Sigma-Aldrich
1-Naphthylamin, 97%
Sigma-Aldrich
N-Phenyl-1-naphthylamin, reagent grade, 98%
Millipore
Nitratreagens A, suitable for microbiology
Supelco
1-Naphthylamin, analytical standard