Effect of bile on the lipid composition and surface properties of bifidobacteria.
OBJECTIVE
The changes produced on the bacterial surface of Bifidobacteria cells when they are grown in bile were compared with those provoked by bile added to bacteria grown in the absence of bile.


RESULTS
The adhesive properties, the zeta potential and the lipid composition of Bifidobacterial strains, isolated from human faeces and grown in MRS medium, were determined. Bacteria grown in MRS with bile showed a loss of adherence and autoaggregation in correlation with a decrease in the surface hydrophobicity in comparison to those grown in MRS without bile, concomitant with the absence of two glycolipids, the increase of sugar content and minor changes in fatty acid composition. The surface changes caused by bile shock on bacteria grown in bile-free medium were much less pronounced and, in addition, no effect on the lipid composition was apparent.


CONCLUSIONS
The comparison of the results indicates that bile action on surface properties is related to metabolic changes.


CONCLUSIONS
Long-term exposure of bacteria to bile may cause metabolic changes affecting their adhesive properties irreversibly. This may be taken as a criterion to define the probiotic properties of different strains.
Gómez Zavaglia
A
A
Facultad de Farmacia y Bioquímica, Universidad Nacional de Buenos Aires, Buenos Aires, Argentina.
Kociubinski
G
G
Pérez
P
P
Disalvo
E
E
De Antoni
G
G
D001422:Bacterial Adhesion / Q000502:physiology; D001644:Bifidobacterium / Q000737:chemistry* / Q000254:growth & development / Q000378:metabolism / Q000502:physiology; D001646:Bile / Q000502:physiology*; D018938:Caco-2 Cells; D050260:Carbohydrate Metabolism; D002241:Carbohydrates / Q000032:analysis; D002308:Cardiolipins / Q000032:analysis / Q000378:metabolism; D002478:Cells, Cultured; D003470:Culture Media; D005227:Fatty Acids / Q000032:analysis / Q000378:metabolism; D006017:Glycolipids / Q000032:analysis / Q000378:metabolism; D006801:Humans; D057927:Hydrophobic and Hydrophilic Interactions; D050356:Lipid Metabolism; D016017:Odds Ratio; D010715:Phosphatidylglycerols / Q000378:metabolism; D010758:Phosphorus / Q000032:analysis / Q000378:metabolism; D013499:Surface Properties
D002241:Carbohydrates; D002308:Cardiolipins; D003470:Culture Media; D005227:Fatty Acids; D006017:Glycolipids; D010715:Phosphatidylglycerols; D010758:Phosphorus