Influence of preadsorbed milk proteins on adhesion of Listeria monocytogenes to hydrophobic and hydrophilic silica surfaces

Abstract

The adsorption of β-lactoglobulin, bovine serum albumin, α-lactalbumin, and β-casein for 8 h and β-lactoglobulin and bovine serum albumin for 1 h at silanized silica surfaces of low and high hydrophobicity, followed by incubation in buffer and contact with Listeria monocytogenes, resulted in different numbers of cells adhered per unit of surface area. Adhesion to both surfaces was greatest when β-lactoglobulin was present and was lowest when bovine serum albumin was present. Preadsorption of α-lactalbumin and β- casein showed an intermediate effect on cell adhesion. Adsorption of β- lactoglobulin for 1 h resulted in a generally lower number of cells adhered compared with the 8-h adsorption time, while the opposite result was observed with respect to bovine serum albumin. The adhesion data were explainable in terms of the relative rates of arrival to the surface and postadsorptive conformational change among the proteins, in addition to the extent of surface coverage in each case.