Cell surface hydrophobicity of Bifidobacterium bifidum subsp. pennsylvanicum.

The possible role of lipoteichoic acid with respect to cell surface properties of Bifidobacterium bifidum subsp. pennsylvanicum was studied. Standard suspensions of bacteria were mixed with octane or xylene. B. bifidum subsp. pennsylvanicum was shown to possess a strongly hydrophobic cell surface. Hydrophobicity of the bacteria could be reduced by treatment with trypsin, pepsin (at pH 4.5), HCl and penicillin. The latter treatment resulted in an increased excretion of lipoteichoic acid. Albumin was capable of inhibiting the adherence to octane when it was present in the assay buffer. The data suggest that both protein and lipoteichoic acid may be involved in cell surface hydrophobicity. A great divergence in cell surface properties was observed within the genus Bifidobacterium.