The hydrophobic characteristics of the cell surface of both
strains were evaluated by the microbial adhesion to hexadecane
(MATH) assay, previously described by Deepika et al. (2009). Probiotic
strains were cultured in MRS for 24 h at 37 C. The culture
broths were centrifuged (5000 g for 10 min, 4 C), and cells washed
twice in Phosphate Buffer Saline (PBS) before suspending in
10 mmol L1 KH2PO4 (Sigma). The pH of the bacterial suspension
was adjusted to 3 with 1 mol L1 HCl to minimise the electrostatic
interactions between bacterial cells and hexadecane and the initial
absorbance (A0) at 600 nm adjusted to 0.8. The absorbance was
measured using a Spectrophotometer BioMate 3 (Thermo Electron
Corporation, Madison, WI, USA). Two millilitres of bacterial suspension
was then mixed with the same volume of hexadecane
(Sigma) in a 10mL syringe. The mixturewas vortexed for 1 min and
then left undisturbed for 20 min to allow complete phase separation.
After equilibration, the lower aqueous phase was removed carefully, in order not to disturb the interfacial equilibrium, into
plastic spectrophotometry cuvettes and absorbance at 600 nm (A1)
measured. Strains adhering well (>80%) to the hydrocarbons are
considered to be hydrophobic and strains adhering poorly (